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Spinal cord, peripheral nerves & neuromuscular junction
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A Case of Mitochondrial Encephalomyopathy with Cytochrome c Oxydase DeficiencY Norihiko Tsuda, MD, Eikichi Miyashiro, MD, Shogo Kihira, MD, Toshihiko Yanagawa, MD, Shigeaki Miyabayashi, MD and Ikuya Nonaka, MD Department of Pediatrics, Wakayama Rosai Hospital, Wakayama (NT, EM); Department of Pediatrics, Wakayama Medical College, Wakayama (SK, TY); Department of Pediatrics, Tohoku University School of Medicine, Sendai, Miyagi (SM); National Center for Nervous, Mental and Muscular Disorders, Kodaira, Tokyo (IN)
Effects of High-Dose Prednisolone in a Case of Chronic Relapsing Dysimmune Polyneuropathy (CRDP) Keiichi Taku, MD, Teruhisa Miike, MD and Tadashi Ushijim a, MD Departments of Child Development (KT, TM) and Pediatrics (TU), Kumamoto University Medical School, Kumamoto
We report a case of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), whose muscle cytochrome c oxidase activity was decreased. The patient had developed normally until age 8 when left ptosis, visual impairment, failure of memory, homonymous hemianopia and WPW syndrome on ECG were noted. From 9 years, hearing loss and clonic convulsions, predominantly on the left side of the body, appeared. Episodes of status epilepticus and vomiting repeatedly occurred with worsening of hearing and motor function and occasionally hemiparesis. Mental regression, visual impairment, hearing loss, muscle weakness and muscular atrophy gradually progressed, and she became unable to walk without assistance or to speak. On examination at age 14 years, she was apathetic and emaciated with no signs of sexual maturity. Marked hirsutism, a myopathic face, left ptosis, left external strabismus, hearing loss, muscular atrophy and muscle weakness were noted. The blood lactate and pyruvate levels were high (51.0 mg/dl and 1.35 mg/dl, respectively), and those of CSF were also high (62.6 mg/dl and 2.20 mg/dl, respectively). The CSF protein concentration was high (97 mg/dl). Aminoaciduria was absent. Marked brain atrophy, calcification of the basal ganglia and scattered low-density areas in the cortical and subcortical regions were evident on CTscanning. ECG and ECHO cardiography revealed cardiomyopathy and WPW syndrome. A biopsy of the biceps muscle showed numerous ragged-red fibers on modified Gomori trichrome staining, and cytochrome c oxidase staining revealed that most fibers exhibited almost no activity. Cytochrome c oxidase activity of the muscle was about half the normal level, and the other enzyme activities of the electron transport system were normal. In cultured fibroblasts from a skin biopsy, cytochrome c oxidase activity was normal. At age 15 years, she died of suffocation due to vomited matter. This case differs in the presence of cardiomyopathy, marked hirsutism and the high CSF protein concentration from the reported cases of MELAS.
Key words: Mitochondrial encephalomyopathy, MELAS, cytochrome c oxidase, lactic acidemia.
234 Brain & Development, Vol 9, No 2,1987
Many authors have reported and discussed efficacy of corticosteroids therapy for children with chronic relapsing dysimmune polyneuropathy (CRDP). We report a case of CRDP who showed a good outcome with high-dose prednisolone therapy according to the method recommended by W.K. Engel. A 10-year-old boy was admitted to our hospital because of weakness of the whole body. He had exhibited the same symptom one year previously, and so was admitted to another hospital for about a month, where he was treated with prednisolone, and he partially recovered his health. On admission to our hospital, his hands and feet appeared to be severely atrophic, and he could not stand up by himself. His nerve conduction velocity was markedly decreased, and CSF analysis revealed an increased protein concentration (66 mg/dl) and normal cell counts (I/3/mm 3 ). Prednisolone therapy was started, 1.5 mg/kg daily, and he recovered his health in about 3 months. During the next 3 months, the drug was gradually reduced; at present he is on maintenance therapy (5 mg every other day). CRDP occurs rarely in childhood, and the efficacy of corticosteroids is not clear. This case suggests that highdose prednisolone therapy for children with CRDP is beneficial.
Key words: CRDP, high-dose prednisolone.
287
Two Sisters Showing Congenital Insensitivity to Pain with Anhidrosis Including One Autopsy Case . Koichiro Kawashima, MD, Kenzo Hamano, MD, Toshiyuki Suzuki, MD, Junko Fujiwara, MD, Hitoshi Takita, MD, Keiko Suzuki, MD and Takesaburo Ogata, MD Divisions of Pediatrics (KK, KH, TS, JF, HT) and Pathology (KS, TO), Institute of Clinical Medicine, The University of Tsukuba, Ibaraki Congenital insensitivity to pain with anhidrosis (CIPA) is a rare genetic disease, characterized by insensitivity to pain with normal tactile perception, absence of sweating, recurrent unexplained fever, self-mutilation, mental retardation and histologically normal sweat glands. To date, only one autopsy case has been reported, by Swanson. We reported two sisters with CIP A, including one autopsy case. They were born to consanguineous Japanese parents.
Case 1 A two-week-old neonate, after a full-term normal delivery and an uneventful pregnancy, showed mild muscle hypotonia and poor responsiveness to pain at birth. She became febrile at 14 days after birth and was diagnosed as having a mild form of pneumonia, which had improved a week later. Following this improvement, unexplained intermittent fever was frequently observed. Sweating was absent even during the febrile and suckling periods. There was no response to pinprick pain. A skin biopsy was performed without anesthesia, and normal sweat glands were observed. She died at 2 months old from respiratory failure after vomiting. Case 2 A two-year-old girl, the elder sister of the case 1, has shown unexplained fever episodes since 3 months old and self-mutilation since initial dentition at 4 months old. Similar to in the younger sister, sweating and responsiveness to pain were not recognized. A skin biopsy specimen revealed that sweat glands were morphologically normal but a histochemical study of the glands showed decreased acetylcholinesterase activity. Autopsy Findings The most remarkable macroscopic finding was hypoplastic adrenal glands. The histopathological findings were: 1, loss of small neurons of the dorsal root ganglia; 2, lack of small fibers in the dorsal roots; and 3, hypoplasia of Lissauer's tract. No pathological changes were recognized in the trigeminal ganglia, spinothalamic tract, thalamus or cerebral cortex. As to EM findings, unmyelinated fibers and small myelinated fibers in the sural nerve were markedly reduced in number.
Key words: Congenital insensitivity to pain with anhidrosis, autopsy, neural crest.
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A Case of Atypical Juvenile Progressive Spinal Muscular Atrophy Tomoaki Nagaura, MD, Kiyoomi Sumi, MD, Jiro Abe, MD and Shigeo Hashimoto, MD Department of Pediatrics, Osaka Kouseinenkin Hospital, Osaka (TN, KS); Department of Pediatric Neurology, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka (JA); Department of Second Pathology, Kinki Medical School, Osaka (SH) A case with atypical progressive muscular atrophy was reported. The patient was an 8-year-old girl, whose illness began before 2 years of age with weakness and muscular atrophy. At 8 years of age, muscular atrophy was especially evident in the distal parts of the lower extremities and the proximal parts of the upper extremities. Muscular fasciCUlation was not observed and all tendon reflexes were diminished or abolished. The serum CK and aldolase levels were slightly elevated. Motor nerve conduction velocities were within normal limits. An EMG study revealed neuropathic changes in the biceps brachii and anterior tibial muscles, but not in the rectus femoris or abductor pollicis brevis muscle. The fibularis brevis muscle obtained on biopsying showed neuropathic changes including fiber type grouping and small angular fibers. The histological findings for the sural nerve were within normal limits. Judging from the age of onset and clinical course, this condution was thought to be similar to juvenile progressive spinal muscular atrophy, but in the distribution of atrophied muscles it resemble neurogenic scapuloperoneal muscular atrophy. This condition was suggested to be between juvenile progressive spinal muscular atrophy and scapuloperoneal muscular atrophy.
Key words: Juvenile progressive spinal muscular atrophy, scapuloperoneal muscular atrophy.
Conclusion We found hypoplasia of the adrenal glands, of which Swanson did not make any mention in 1965. Both the adrenal glands and the spinal dorsal root ganglia are known to be of neural crest origin. The above findings suggest that CIPA is caused by the abnormal development of the neural crest.
Brain & Development, Vol 9, No 2,1987 235
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A Patient with Eaton-Lambert Syndrome Associated with Rhabdomyosarcoma
Clinical and Histochemical Studies on Patients with Myotonic Dystrophy-EspeciallY the Congenital Form
Michihiro Hatano, MD, Yuko Umeda, MD, Hiroshi Tada, MD and Masahiro Tsuchida, MD Department of Pediatrics, School of Medicine, Toho University, Tokyo
Shuji Wakai, MD, Masato Nagaoka, DDS, Ryoji Minami, MD and Nobutada Tachi, MD The National Yakumo Hospital, Yakumo, Hokkaido (SW, MN, RM); Department of Pediatrics, Sapporo Medical College, Sapporo, Hokkaido (NT)
Eaton-Lambert syndrome (ELS) is a myasthenic syndrome, associated with a malignant disease in most cases. The occurrence of ELS in childhood is very rare. We experienced a case of this syndrome associated with rhabdomyosarcoma of the prostata in a young patient. Case Report A one-year, 8-month-old boy visited our hospital because of difficulty in urination. He was diagnosed as having a prostate tumor. Resection of the tumor was undertaken but with incomplete results. The pathological diagnosis was rhabdomyosarcoma. Strong chemotherapy, including cyclophosphamide and vincristine, was given. One month after the beginning of this therapy, he developed ptosis of both eyelids. Neurological examination showed muscle weakness, dominantly at lower extremities, a decrease in muscle tone and a loss of deep tendon reflexes. MendelBechterew reflex and Rossolimo reflex were positive. Abduction of the eye balls was limited. Several days later, he developed dysphagia and dyspnea. The relapse of the tumor was not recognized. High-frequency stimulating electromyography of the brachial plexus inducted from the deltoid muscle showed low initial amplitude (1.2 mV) and marked waxing (400%). Tensilon test was negative. There were no abnormal findings in his cranial CT scan, peripheral nerve conduction velocity or cerebrospinal fluid. We diagnosed him as having ELS and treated him with guanidine HCl 40 mg/kg/day orally . All symptoms improved in a few weeks. He showed no recurrence after cessation of the administration of the drug. He showed an unstable gait at consolidation chemotherapy. He is now 2 years, 8 months old and shows a slightly unstable gait and pathological reflexes. High-frequency stimulating electromyography shows normal findings. Discussion Though it is suspected that some immunological mechanism brings about this syndrome, our patient was treated with an immunosuppressive agent. Thus, an immunological mechanism is not likely in our patient. Our patient developed his symptoms during administration of anticancer agents, and after improvement he showed transient unstable gait at another administration of anticancer agents. So we think that there may be some relationship between the occurrence of ELS and the aliministration of anticancer agents, and we are especially suspicious of vincristine which has neurotoxic properties. Key words: Rhabdomyosarcoma, Eaton-Lambert syndrome, vincristine.
236 Brain & Development, Vol 9, No 2,1987
Clinical and muscle histopathological findings in patients with myotonic dystrophy (MyD) were studied, especially the congenital form and three with the adult form. Muscle biopsies were performed in nine of the thirteen patients (eight with the congenital form, one with the adult form). The clinical and histopathological features of the child patients with the congenital form can be summarized as follows: neonatal hypotonia, feeding difficulties and asphyxia at birth were seen in nine, seven and four of the thirteen patients, respectively. The mothers of the nine patients were found to have the adult form and one father was ~ffected. Distal limb weakness, wasting, mental retardation, myopathic face and talipes equinus were recognized in all patients. Symptoms such as myotonia, lens opacities and malocclusion tended to appear between about five and seven years of age. Patellar tendon reflexes were exaggerated in two patients. The patients showing apparent hypersomnia and bradycardia were all over 11 years old. Serum CK levels were within normal limits or moderately raised in most patients. The TRH test with TSH hyperreaction was observed in three patients, and an increased response to glucose loading was seen in seven patients. The NCV results were all within normal range. On ECG sinus bradycardia and/or grade I A-V block were seen as the main findings in five child patients. On echocardiography three of the eight patients examined showed mitral valve prolapse. Cortical atrophy and mild ventricular dilation were the main findings seen on brain CT scanning in most patients. Muscle biopsy specimens were obtained from the left anterior tibial muscles in all cases. In the child patients with the congenital form, particularly those between 5 and 11 years old, the intermyofibrillar networks were well preserved in spite of the hypotonia seen in the neonatal period. The finding of marked type 1 fiber predominance was observed in many patients. The cases with remarkable talipes equinus due to contractures of the Achilles tendons had fascicles composed of many round atrophic fibers with proliferation of the endomysial connective tissues suggesting neuropathic changes. Key words: Myotonic dystrophy, congenital form type 1 fiber predominance, neuropathic change.
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A Case of Mitochondrial Encephalomyopathy with Cytochrome c Oxydase DeficiencY Norihiko Tsuda, MD, Eikichi Miyashiro, MD, Shogo Kihira, MD, Toshihiko Yanagawa, MD, Shigeaki Miyabayashi, MD and Ikuya Nonaka, MD Department of Pediatrics, Wakayama Rosai Hospital, Wakayama (NT, EM); Department of Pediatrics, Wakayama Medical College, Wakayama (SK, TY); Department of Pediatrics, Tohoku University School of Medicine, Sendai, Miyagi (SM); National Center for Nervous, Mental and Muscular Disorders, Kodaira, Tokyo (IN)
Effects of High-Dose Prednisolone in a Case of Chronic Relapsing Dysimmune Polyneuropathy (CRDP) Keiichi Taku, MD, Teruhisa Miike, MD and Tadashi Ushijim a, MD Departments of Child Development (KT, TM) and Pediatrics (TU), Kumamoto University Medical School, Kumamoto
We report a case of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), whose muscle cytochrome c oxidase activity was decreased. The patient had developed normally until age 8 when left ptosis, visual impairment, failure of memory, homonymous hemianopia and WPW syndrome on ECG were noted. From 9 years, hearing loss and clonic convulsions, predominantly on the left side of the body, appeared. Episodes of status epilepticus and vomiting repeatedly occurred with worsening of hearing and motor function and occasionally hemiparesis. Mental regression, visual impairment, hearing loss, muscle weakness and muscular atrophy gradually progressed, and she became unable to walk without assistance or to speak. On examination at age 14 years, she was apathetic and emaciated with no signs of sexual maturity. Marked hirsutism, a myopathic face, left ptosis, left external strabismus, hearing loss, muscular atrophy and muscle weakness were noted. The blood lactate and pyruvate levels were high (51.0 mg/dl and 1.35 mg/dl, respectively), and those of CSF were also high (62.6 mg/dl and 2.20 mg/dl, respectively). The CSF protein concentration was high (97 mg/dl). Aminoaciduria was absent. Marked brain atrophy, calcification of the basal ganglia and scattered low-density areas in the cortical and subcortical regions were evident on CTscanning. ECG and ECHO cardiography revealed cardiomyopathy and WPW syndrome. A biopsy of the biceps muscle showed numerous ragged-red fibers on modified Gomori trichrome staining, and cytochrome c oxidase staining revealed that most fibers exhibited almost no activity. Cytochrome c oxidase activity of the muscle was about half the normal level, and the other enzyme activities of the electron transport system were normal. In cultured fibroblasts from a skin biopsy, cytochrome c oxidase activity was normal. At age 15 years, she died of suffocation due to vomited matter. This case differs in the presence of cardiomyopathy, marked hirsutism and the high CSF protein concentration from the reported cases of MELAS.
Key words: Mitochondrial encephalomyopathy, MELAS, cytochrome c oxidase, lactic acidemia.
234 Brain & Development, Vol 9, No 2,1987
Many authors have reported and discussed efficacy of corticosteroids therapy for children with chronic relapsing dysimmune polyneuropathy (CRDP). We report a case of CRDP who showed a good outcome with high-dose prednisolone therapy according to the method recommended by W.K. Engel. A 10-year-old boy was admitted to our hospital because of weakness of the whole body. He had exhibited the same symptom one year previously, and so was admitted to another hospital for about a month, where he was treated with prednisolone, and he partially recovered his health. On admission to our hospital, his hands and feet appeared to be severely atrophic, and he could not stand up by himself. His nerve conduction velocity was markedly decreased, and CSF analysis revealed an increased protein concentration (66 mg/dl) and normal cell counts (I/3/mm 3 ). Prednisolone therapy was started, 1.5 mg/kg daily, and he recovered his health in about 3 months. During the next 3 months, the drug was gradually reduced; at present he is on maintenance therapy (5 mg every other day). CRDP occurs rarely in childhood, and the efficacy of corticosteroids is not clear. This case suggests that highdose prednisolone therapy for children with CRDP is beneficial.
Key words: CRDP, high-dose prednisolone.
287
Two Sisters Showing Congenital Insensitivity to Pain with Anhidrosis Including One Autopsy Case . Koichiro Kawashima, MD, Kenzo Hamano, MD, Toshiyuki Suzuki, MD, Junko Fujiwara, MD, Hitoshi Takita, MD, Keiko Suzuki, MD and Takesaburo Ogata, MD Divisions of Pediatrics (KK, KH, TS, JF, HT) and Pathology (KS, TO), Institute of Clinical Medicine, The University of Tsukuba, Ibaraki Congenital insensitivity to pain with anhidrosis (CIPA) is a rare genetic disease, characterized by insensitivity to pain with normal tactile perception, absence of sweating, recurrent unexplained fever, self-mutilation, mental retardation and histologically normal sweat glands. To date, only one autopsy case has been reported, by Swanson. We reported two sisters with CIP A, including one autopsy case. They were born to consanguineous Japanese parents.
Case 1 A two-week-old neonate, after a full-term normal delivery and an uneventful pregnancy, showed mild muscle hypotonia and poor responsiveness to pain at birth. She became febrile at 14 days after birth and was diagnosed as having a mild form of pneumonia, which had improved a week later. Following this improvement, unexplained intermittent fever was frequently observed. Sweating was absent even during the febrile and suckling periods. There was no response to pinprick pain. A skin biopsy was performed without anesthesia, and normal sweat glands were observed. She died at 2 months old from respiratory failure after vomiting. Case 2 A two-year-old girl, the elder sister of the case 1, has shown unexplained fever episodes since 3 months old and self-mutilation since initial dentition at 4 months old. Similar to in the younger sister, sweating and responsiveness to pain were not recognized. A skin biopsy specimen revealed that sweat glands were morphologically normal but a histochemical study of the glands showed decreased acetylcholinesterase activity. Autopsy Findings The most remarkable macroscopic finding was hypoplastic adrenal glands. The histopathological findings were: 1, loss of small neurons of the dorsal root ganglia; 2, lack of small fibers in the dorsal roots; and 3, hypoplasia of Lissauer's tract. No pathological changes were recognized in the trigeminal ganglia, spinothalamic tract, thalamus or cerebral cortex. As to EM findings, unmyelinated fibers and small myelinated fibers in the sural nerve were markedly reduced in number.
Key words: Congenital insensitivity to pain with anhidrosis, autopsy, neural crest.
288
A Case of Atypical Juvenile Progressive Spinal Muscular Atrophy Tomoaki Nagaura, MD, Kiyoomi Sumi, MD, Jiro Abe, MD and Shigeo Hashimoto, MD Department of Pediatrics, Osaka Kouseinenkin Hospital, Osaka (TN, KS); Department of Pediatric Neurology, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka (JA); Department of Second Pathology, Kinki Medical School, Osaka (SH) A case with atypical progressive muscular atrophy was reported. The patient was an 8-year-old girl, whose illness began before 2 years of age with weakness and muscular atrophy. At 8 years of age, muscular atrophy was especially evident in the distal parts of the lower extremities and the proximal parts of the upper extremities. Muscular fasciCUlation was not observed and all tendon reflexes were diminished or abolished. The serum CK and aldolase levels were slightly elevated. Motor nerve conduction velocities were within normal limits. An EMG study revealed neuropathic changes in the biceps brachii and anterior tibial muscles, but not in the rectus femoris or abductor pollicis brevis muscle. The fibularis brevis muscle obtained on biopsying showed neuropathic changes including fiber type grouping and small angular fibers. The histological findings for the sural nerve were within normal limits. Judging from the age of onset and clinical course, this condution was thought to be similar to juvenile progressive spinal muscular atrophy, but in the distribution of atrophied muscles it resemble neurogenic scapuloperoneal muscular atrophy. This condition was suggested to be between juvenile progressive spinal muscular atrophy and scapuloperoneal muscular atrophy.
Key words: Juvenile progressive spinal muscular atrophy, scapuloperoneal muscular atrophy.
Conclusion We found hypoplasia of the adrenal glands, of which Swanson did not make any mention in 1965. Both the adrenal glands and the spinal dorsal root ganglia are known to be of neural crest origin. The above findings suggest that CIPA is caused by the abnormal development of the neural crest.
Brain & Development, Vol 9, No 2,1987 235
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A Patient with Eaton-Lambert Syndrome Associated with Rhabdomyosarcoma
Clinical and Histochemical Studies on Patients with Myotonic Dystrophy-EspeciallY the Congenital Form
Michihiro Hatano, MD, Yuko Umeda, MD, Hiroshi Tada, MD and Masahiro Tsuchida, MD Department of Pediatrics, School of Medicine, Toho University, Tokyo
Shuji Wakai, MD, Masato Nagaoka, DDS, Ryoji Minami, MD and Nobutada Tachi, MD The National Yakumo Hospital, Yakumo, Hokkaido (SW, MN, RM); Department of Pediatrics, Sapporo Medical College, Sapporo, Hokkaido (NT)
Eaton-Lambert syndrome (ELS) is a myasthenic syndrome, associated with a malignant disease in most cases. The occurrence of ELS in childhood is very rare. We experienced a case of this syndrome associated with rhabdomyosarcoma of the prostata in a young patient. Case Report A one-year, 8-month-old boy visited our hospital because of difficulty in urination. He was diagnosed as having a prostate tumor. Resection of the tumor was undertaken but with incomplete results. The pathological diagnosis was rhabdomyosarcoma. Strong chemotherapy, including cyclophosphamide and vincristine, was given. One month after the beginning of this therapy, he developed ptosis of both eyelids. Neurological examination showed muscle weakness, dominantly at lower extremities, a decrease in muscle tone and a loss of deep tendon reflexes. MendelBechterew reflex and Rossolimo reflex were positive. Abduction of the eye balls was limited. Several days later, he developed dysphagia and dyspnea. The relapse of the tumor was not recognized. High-frequency stimulating electromyography of the brachial plexus inducted from the deltoid muscle showed low initial amplitude (1.2 mV) and marked waxing (400%). Tensilon test was negative. There were no abnormal findings in his cranial CT scan, peripheral nerve conduction velocity or cerebrospinal fluid. We diagnosed him as having ELS and treated him with guanidine HCl 40 mg/kg/day orally . All symptoms improved in a few weeks. He showed no recurrence after cessation of the administration of the drug. He showed an unstable gait at consolidation chemotherapy. He is now 2 years, 8 months old and shows a slightly unstable gait and pathological reflexes. High-frequency stimulating electromyography shows normal findings. Discussion Though it is suspected that some immunological mechanism brings about this syndrome, our patient was treated with an immunosuppressive agent. Thus, an immunological mechanism is not likely in our patient. Our patient developed his symptoms during administration of anticancer agents, and after improvement he showed transient unstable gait at another administration of anticancer agents. So we think that there may be some relationship between the occurrence of ELS and the aliministration of anticancer agents, and we are especially suspicious of vincristine which has neurotoxic properties. Key words: Rhabdomyosarcoma, Eaton-Lambert syndrome, vincristine.
236 Brain & Development, Vol 9, No 2,1987
Clinical and muscle histopathological findings in patients with myotonic dystrophy (MyD) were studied, especially the congenital form and three with the adult form. Muscle biopsies were performed in nine of the thirteen patients (eight with the congenital form, one with the adult form). The clinical and histopathological features of the child patients with the congenital form can be summarized as follows: neonatal hypotonia, feeding difficulties and asphyxia at birth were seen in nine, seven and four of the thirteen patients, respectively. The mothers of the nine patients were found to have the adult form and one father was ~ffected. Distal limb weakness, wasting, mental retardation, myopathic face and talipes equinus were recognized in all patients. Symptoms such as myotonia, lens opacities and malocclusion tended to appear between about five and seven years of age. Patellar tendon reflexes were exaggerated in two patients. The patients showing apparent hypersomnia and bradycardia were all over 11 years old. Serum CK levels were within normal limits or moderately raised in most patients. The TRH test with TSH hyperreaction was observed in three patients, and an increased response to glucose loading was seen in seven patients. The NCV results were all within normal range. On ECG sinus bradycardia and/or grade I A-V block were seen as the main findings in five child patients. On echocardiography three of the eight patients examined showed mitral valve prolapse. Cortical atrophy and mild ventricular dilation were the main findings seen on brain CT scanning in most patients. Muscle biopsy specimens were obtained from the left anterior tibial muscles in all cases. In the child patients with the congenital form, particularly those between 5 and 11 years old, the intermyofibrillar networks were well preserved in spite of the hypotonia seen in the neonatal period. The finding of marked type 1 fiber predominance was observed in many patients. The cases with remarkable talipes equinus due to contractures of the Achilles tendons had fascicles composed of many round atrophic fibers with proliferation of the endomysial connective tissues suggesting neuropathic changes. Key words: Myotonic dystrophy, congenital form type 1 fiber predominance, neuropathic change.