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MR imaging in hypertrophic neuropathy: A case of hereditary motor and sensory neuropathy, type i (charcot-marie-tooth)
204
CLINICAL IMAGING 1990;14:204-207
MR IMAGING IN HYPERTROPHIC NEUROPATHY: A CASE OF HEREDITARY MOTOR AND SENSORY NEUROPATHY, TYPE 1 (CHARCOT-MARIE-TOOTH) SAMUEL K. CHOI, MD, ROGER P. BOWERS, PAUL E. BUCKTHAL, MD
We describefindings ofCharcot-Marie-Tooth disease in magnetic resonance imaging (MRI). The MRI examination of the Iumbar spine with and without gadolinium DTPA showed diffusely enlarged cauda equina, nerve roots, and ganglia. In the setting of appropriate family history and clinical presentation, the findings of diffusely enlarged nerve roots support the diagnosis of hereditary motor and sensory neuropathy, Type I (HMSN I, Charcot-MarieTooth). KEY WORDS:
Charcot-Marie-Tooth imaging of spine;
disease; Magnetic resonance Enlargement of nerve roots
CASE REPORT A 4i-year-old Caucasian man was referred for magnetic resonance imaging (MRI) of the lumbosacral spine for further evaluation of chronic back pain. Computed tomography (CT) at another institution was nonspecific but showed the possibility of a conjoined nerve root at L5-Sl on the right side. The patient gave a history of long-standing backache since age 23 years. His back problem was aggravated by a car accident approximately 1 year ago. The
From the Department of Radiology (S.K.C., R.P.B.) and the Department of Neurology (P.E.B.), Guthrie Medical CenterlRobert Packer Hospital, Guthrie Square, Sayre, Pennsylvania. Address reprint requests to: Samuel K. Choi, MD, Department of Radiology, Guthrie Medical Center, Sayre, PA 18840. Received February 5, 1990. 0 1990 by Elswier Science Publishing Co., Inc. 655 Avenue of the Americas, 0899/7071/90/$3.50
New York, NY 10010
MD,
AND
patient described the back pain as diffuse, nonlocalizing with tight feeling in his right buttock. Neurologie examination on this admission showed decreased tendon reflexes of the lower extremities bilaterally, slight diminished pain sensation at the lateral aspect of both feet, mild weakness of dqrsiflexion and eversion of ankles and high-arched feet. There was no tremor. His mother and a brother have been diagnosed with Charcot-Marie-Tooth disease (CMTD) which was nerve biopsy proven. The T2weighted sagittal MRI of the lumbosacral spine showed low to intermediate signal intensity of the spinal canal (Figure 1). The axial stans show the thecal sac nearly completely filled with nerve roots which are mildly enhanced with gadolinium DTPA (Figure 2). The exiting nerve roots and ganglia were markedly enlarged (Figure 3). The plain films of the lumbar spine were normal. There was no significant scalloping of vertebral bodies. A myelogram showed diffuse, smooth enlargement of the nerve roots, although the finding was not so obvious as that seen in the MRI (Figure 4). Fluoroscopically, the flow of the contrast medium from the lumbar region to a higher leve1 was markedly delayed with table tilting. The cerebrospinal fluid protein was elevated to 79 mg%. In an electrophysiologic study, the nerve conduction velocities and distal latencies were markedly delayed in upper and lower extremities. The electromyography showed high amplitude activity with fasciculation and spontaneous activity. DISCUSSION Charcot-Marie-Tooth disease, also known as hereditary motor and sensory neuropathy, Type 1 (HMSNI), is an autosomal dominant genetic disorder mapped
AUGUST 1990
to chromosome 1 by linkage to the Duffy blood group. Sporadic cases are not linked and are heterogeneous (1). The usual onset of the disorder is during late childhood or adolescence. The disorder results in chronic degeneration of peripheral nerves and roots resulting in distal muscle atrophy, beginning in the feet and legs and later involving the hands (2). The atrophied legs have been referred to as having a stork-leg appearance. Repeated demyelinating and remyelinating responses in the nerve to axonal atrophy produce diffuse enlargement of nerves. There is an increase in connective tissue, both perineural and epineural, and also an increase in endoneural collagen (2, 3). Occasionally, these enlarged peripheral nerves can be palpated on examination. The radiologie diagnosis of hypertrophic motor and sensory neuropathy has been made by plain film, myelogram, and CT in the past (4-6). The plain film examination showed scalloping of the posterior vertebral bodies, concavity on the inner aspect of the pedicles, and increase in interpeduncular distances.
HYPERTROPHIC NEUROPATHY
205
FIGURE 1. (A) Sagittal Tl-weighted image (TR 550, TE 20) shows intermediate signal intensity of lumbar thecal sac rather than usual low signal intensity. (B) TB-weighted image (TR 2600, TE 90) shows low to intermediate signal
intensity of thecal sac rather than usual high signal intensity. These signal intensity changes are due to increase in size of the roots of cauda equina and relative decrease in cerebrospinal fluid volume. The high signal intensity in the region of distal spinal cord is artifactual.
Myelogram and postmyelogram shown enlarged roots.
CT
stans
have
The enlarged nerve roots can also be seen in hypertrophic motor and sensory neuropathy, type 111 (Dejerine-Sottas), and differentiation from CMTD is difficult to detect, both clinically and radiologically. Dejerine-Sottas disease (DSD) has an earlier age of onset, a recessive mode of inheritance, and a greater severity of the disorder, such as more ataxie and areflexie, with more prominent nerve root enlargement
206
CHOI ET AL.
CLINICAL IMAGING VOL. 14, NO. 3
FIGURE 2. (A) Tl-weighted parasagittal image (TR 55 0, TE 20) and (B) axial image at the leve1 of L4-5 show markec AlY enlarged exiting nerve roots and ganglia (arrows).
A axial images (TR 800, TE 15) at the leve1 of L3 before and (B) after injection of gadolinil urn FIGURE 3. (A) Tl-weighted DTPA show mild uniform enhancement of gangha and cauda equina. Enlarged individual roots of cauda equina are a ISO seen. The higher signal intensity in the region of the ri ght neural foramen is artifactual.
AUGUST
HYPERTROPHIC
1990
NEUROPATHY
207
and more focal nerve enlargement as compared to CMTD. When there is low to intermediate signal intensity of the lumbar thecal sac in TZ-weighted images due to a relative decrease in cerebrospinal fluid volume resulting from an increase in soft tissue volume, one would carefully examine the size of exiting nerve roots. The pattern of gadolinium enhancement is mild, uniform, and symmetrical. This enhancement pattern would be helpful in distinguishing CMTD from some other processes in the differential, especially metastatic disease and arachnoiditis. We believe that the MRI findings can contribute significantly to the diagnosis of CMTD.
REFERENCES 1. Griflìths LR, Zwi MB, McLeod JG, Ross DA. Nicholson GA. Heterogeneity evidente and linkage studies on Charcot-MarieTooth disease. Neurology 1989;39:280-281. 2.
Adams KD, Victor M. Principles of Neurology. McGraw-Hill. 1989; pp. 1056-1057.
ed 3. New York:
3. Ouvrier
FIGURE 4. (A) Anteroposterior lumbar myelogram nerve roots.
show
and diffuse,
lateral smooth
(B) views
of the enlargement of
(2, 3, 7). Pantopaque myelogram of DSD shows diffuse enlargement of the nerve roots (8, 9). However, the myelographic images in other studies show more irregular and less uniform enlargement as compared to our case. Other differential diagnoses of enlarged nerves and nerve roots are diffuse metastasis to cauda equina, recurrent idiopathic polyneuritis, familial amyloidosis, Refsum’s disease, Guillain-Barré syndrome, neurofibromatosis, and acromegaly (2). These diseases have more distinct clinical presentation
RA. McLeod JG. Conchin TE. The hypertrophic of hereditary motor and sensory neuropathy. 1987;110:121-148.
farms Brain
4. Miura T, Hirabuki N, Imakita S, Harada K, Kawai K, Mitomo M. Takahashi M. Radiologie tìndings in a case of Charcot-MarieTooth disease. Br J Radio1 1985;58:1317-1020. 5. Bellon KM, Kaufman B, Tucker Radiology 1972;10:3:319-322,
ME. Hypertrophic
6. Morano JU. Russell WF. Nerve root Marie-Tooth disease: CT appearance.
neuropathy.
enlargement in CharcotKadiology 1986;161:784.
Dyck PJ. Lambert EH. Lower motor and primary diseases with peroneal muscular atrophy. 1968;18:603-618,
sensory Arch
neuron Neurol
Krishna-Kao CVG, Fitz CR, Harwood-Nash LIC. Dejerine-Sottas syndrome in children (hypertrophic interstitial polyneuritis). AJK 1974:122:70-74. Hink VC. Sachdev NS. Myelographic tïndings interstitial neuritis. AJK 1965;95:947-948.
in hypertrophic
CLINICAL IMAGING 1990;14:204-207
MR IMAGING IN HYPERTROPHIC NEUROPATHY: A CASE OF HEREDITARY MOTOR AND SENSORY NEUROPATHY, TYPE 1 (CHARCOT-MARIE-TOOTH) SAMUEL K. CHOI, MD, ROGER P. BOWERS, PAUL E. BUCKTHAL, MD
We describefindings ofCharcot-Marie-Tooth disease in magnetic resonance imaging (MRI). The MRI examination of the Iumbar spine with and without gadolinium DTPA showed diffusely enlarged cauda equina, nerve roots, and ganglia. In the setting of appropriate family history and clinical presentation, the findings of diffusely enlarged nerve roots support the diagnosis of hereditary motor and sensory neuropathy, Type I (HMSN I, Charcot-MarieTooth). KEY WORDS:
Charcot-Marie-Tooth imaging of spine;
disease; Magnetic resonance Enlargement of nerve roots
CASE REPORT A 4i-year-old Caucasian man was referred for magnetic resonance imaging (MRI) of the lumbosacral spine for further evaluation of chronic back pain. Computed tomography (CT) at another institution was nonspecific but showed the possibility of a conjoined nerve root at L5-Sl on the right side. The patient gave a history of long-standing backache since age 23 years. His back problem was aggravated by a car accident approximately 1 year ago. The
From the Department of Radiology (S.K.C., R.P.B.) and the Department of Neurology (P.E.B.), Guthrie Medical CenterlRobert Packer Hospital, Guthrie Square, Sayre, Pennsylvania. Address reprint requests to: Samuel K. Choi, MD, Department of Radiology, Guthrie Medical Center, Sayre, PA 18840. Received February 5, 1990. 0 1990 by Elswier Science Publishing Co., Inc. 655 Avenue of the Americas, 0899/7071/90/$3.50
New York, NY 10010
MD,
AND
patient described the back pain as diffuse, nonlocalizing with tight feeling in his right buttock. Neurologie examination on this admission showed decreased tendon reflexes of the lower extremities bilaterally, slight diminished pain sensation at the lateral aspect of both feet, mild weakness of dqrsiflexion and eversion of ankles and high-arched feet. There was no tremor. His mother and a brother have been diagnosed with Charcot-Marie-Tooth disease (CMTD) which was nerve biopsy proven. The T2weighted sagittal MRI of the lumbosacral spine showed low to intermediate signal intensity of the spinal canal (Figure 1). The axial stans show the thecal sac nearly completely filled with nerve roots which are mildly enhanced with gadolinium DTPA (Figure 2). The exiting nerve roots and ganglia were markedly enlarged (Figure 3). The plain films of the lumbar spine were normal. There was no significant scalloping of vertebral bodies. A myelogram showed diffuse, smooth enlargement of the nerve roots, although the finding was not so obvious as that seen in the MRI (Figure 4). Fluoroscopically, the flow of the contrast medium from the lumbar region to a higher leve1 was markedly delayed with table tilting. The cerebrospinal fluid protein was elevated to 79 mg%. In an electrophysiologic study, the nerve conduction velocities and distal latencies were markedly delayed in upper and lower extremities. The electromyography showed high amplitude activity with fasciculation and spontaneous activity. DISCUSSION Charcot-Marie-Tooth disease, also known as hereditary motor and sensory neuropathy, Type 1 (HMSNI), is an autosomal dominant genetic disorder mapped
AUGUST 1990
to chromosome 1 by linkage to the Duffy blood group. Sporadic cases are not linked and are heterogeneous (1). The usual onset of the disorder is during late childhood or adolescence. The disorder results in chronic degeneration of peripheral nerves and roots resulting in distal muscle atrophy, beginning in the feet and legs and later involving the hands (2). The atrophied legs have been referred to as having a stork-leg appearance. Repeated demyelinating and remyelinating responses in the nerve to axonal atrophy produce diffuse enlargement of nerves. There is an increase in connective tissue, both perineural and epineural, and also an increase in endoneural collagen (2, 3). Occasionally, these enlarged peripheral nerves can be palpated on examination. The radiologie diagnosis of hypertrophic motor and sensory neuropathy has been made by plain film, myelogram, and CT in the past (4-6). The plain film examination showed scalloping of the posterior vertebral bodies, concavity on the inner aspect of the pedicles, and increase in interpeduncular distances.
HYPERTROPHIC NEUROPATHY
205
FIGURE 1. (A) Sagittal Tl-weighted image (TR 550, TE 20) shows intermediate signal intensity of lumbar thecal sac rather than usual low signal intensity. (B) TB-weighted image (TR 2600, TE 90) shows low to intermediate signal
intensity of thecal sac rather than usual high signal intensity. These signal intensity changes are due to increase in size of the roots of cauda equina and relative decrease in cerebrospinal fluid volume. The high signal intensity in the region of distal spinal cord is artifactual.
Myelogram and postmyelogram shown enlarged roots.
CT
stans
have
The enlarged nerve roots can also be seen in hypertrophic motor and sensory neuropathy, type 111 (Dejerine-Sottas), and differentiation from CMTD is difficult to detect, both clinically and radiologically. Dejerine-Sottas disease (DSD) has an earlier age of onset, a recessive mode of inheritance, and a greater severity of the disorder, such as more ataxie and areflexie, with more prominent nerve root enlargement
206
CHOI ET AL.
CLINICAL IMAGING VOL. 14, NO. 3
FIGURE 2. (A) Tl-weighted parasagittal image (TR 55 0, TE 20) and (B) axial image at the leve1 of L4-5 show markec AlY enlarged exiting nerve roots and ganglia (arrows).
A axial images (TR 800, TE 15) at the leve1 of L3 before and (B) after injection of gadolinil urn FIGURE 3. (A) Tl-weighted DTPA show mild uniform enhancement of gangha and cauda equina. Enlarged individual roots of cauda equina are a ISO seen. The higher signal intensity in the region of the ri ght neural foramen is artifactual.
AUGUST
HYPERTROPHIC
1990
NEUROPATHY
207
and more focal nerve enlargement as compared to CMTD. When there is low to intermediate signal intensity of the lumbar thecal sac in TZ-weighted images due to a relative decrease in cerebrospinal fluid volume resulting from an increase in soft tissue volume, one would carefully examine the size of exiting nerve roots. The pattern of gadolinium enhancement is mild, uniform, and symmetrical. This enhancement pattern would be helpful in distinguishing CMTD from some other processes in the differential, especially metastatic disease and arachnoiditis. We believe that the MRI findings can contribute significantly to the diagnosis of CMTD.
REFERENCES 1. Griflìths LR, Zwi MB, McLeod JG, Ross DA. Nicholson GA. Heterogeneity evidente and linkage studies on Charcot-MarieTooth disease. Neurology 1989;39:280-281. 2.
Adams KD, Victor M. Principles of Neurology. McGraw-Hill. 1989; pp. 1056-1057.
ed 3. New York:
3. Ouvrier
FIGURE 4. (A) Anteroposterior lumbar myelogram nerve roots.
show
and diffuse,
lateral smooth
(B) views
of the enlargement of
(2, 3, 7). Pantopaque myelogram of DSD shows diffuse enlargement of the nerve roots (8, 9). However, the myelographic images in other studies show more irregular and less uniform enlargement as compared to our case. Other differential diagnoses of enlarged nerves and nerve roots are diffuse metastasis to cauda equina, recurrent idiopathic polyneuritis, familial amyloidosis, Refsum’s disease, Guillain-Barré syndrome, neurofibromatosis, and acromegaly (2). These diseases have more distinct clinical presentation
RA. McLeod JG. Conchin TE. The hypertrophic of hereditary motor and sensory neuropathy. 1987;110:121-148.
farms Brain
4. Miura T, Hirabuki N, Imakita S, Harada K, Kawai K, Mitomo M. Takahashi M. Radiologie tìndings in a case of Charcot-MarieTooth disease. Br J Radio1 1985;58:1317-1020. 5. Bellon KM, Kaufman B, Tucker Radiology 1972;10:3:319-322,
ME. Hypertrophic
6. Morano JU. Russell WF. Nerve root Marie-Tooth disease: CT appearance.
neuropathy.
enlargement in CharcotKadiology 1986;161:784.
Dyck PJ. Lambert EH. Lower motor and primary diseases with peroneal muscular atrophy. 1968;18:603-618,
sensory Arch
neuron Neurol
Krishna-Kao CVG, Fitz CR, Harwood-Nash LIC. Dejerine-Sottas syndrome in children (hypertrophic interstitial polyneuritis). AJK 1974:122:70-74. Hink VC. Sachdev NS. Myelographic tïndings interstitial neuritis. AJK 1965;95:947-948.
in hypertrophic