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Cervical butterfly-block vertebra a case report
CLINICAL IMAGING 1989;13:167-170
CERVICAL BUTI’ERFLY-BLOCK
167
VERTEBRA
A CASE REPORT MICHAEL SCHLITT, MD, PETER J. DEMPSEY, AND R. KENT ROBINSON, MD
A new type of block vertebml malformation is described. A &‘-year-old woman presented after an akinetic seizure. Routine cervical spine films, obtained because of a recent history of abnormal head posture, disclosed a vertebral anomaly. Computed tomogmphy and conventional polytomography revealed that the lesion was composed of a butterfly vertebm as the upper portion of a pair of nonsegmented vertebme. Vertebral fusion and segmentation anomalies am reviewed and compared with the specific features of this case. KEY WORDS:
Butterfly vertebra; Embryology; IUip,pel-Feil syndrome; Spine Congenital vertebral abnormalities ,are common. The Klippel-Feil syndrome, an abnormality of segmentation defined as two or more congenitally fused cervical vertebra, may occur as frequently as in 1% of spines (l-3). This spinal abnormality is often asymptomatic per se; frequently, associated anomalies in other systems may prove more important to the individual patient (2-8). Anomalies of fusion are less frequently seen and are most commonly manifest as hemivertebrae (4, 9, 10). In contrast to the Klippel-Feil syndrome, asymmetric fusion defects often cause problems directly related to spinal deformity (5). Symmetric fusion defects leading to butter-
From the Department of Neurosurgery, University of South Alabama (M.S.), the Department of Radiology, Knollwood Park Hospital (P.J.D.), and the Department of Neurology, University of South Alabama (R.K.R.). Address reprint requests to: Dr. Michael Schlitt, 714 Mastin, USAMC, 2451 Fillingim St., Mobile, AL 36617. Received September 1988. 0 1989 by Elsevier Science Publishing Co.. Inc. 655 Avenue of the Americas, New York, NY 10010 0899/7071/89/$3.50
MD,
fly or sagittally cleft vertebrae, however, can be asymptomatic. Recently, a 42-year-old woman was admitted with a new onset of seizures. Routine radiographs disclosed a cervical spinal abnormality not previously described that was confirmed by further studies. CASE HISTORY A 42-year-old right-handed woman had been working in her garden on April 5, 1986. She began to feel hot and light-headed and went into the house. Five minutes later she was found by her husband slumped over the sink. No incontinence or tonicclonic movements were seen. She quickly regained consciousness, had no postictal confusion, and was brought to the emergency room. Neurologic examination at the time of admission was normal. However, her husband noted that she had held her head with the chin tilted to the left for some months, for which reason cervical spine x-rays were obtained (Figure 1) that showed a block vertebra composed of the fourth and fifth cervical vertebrae. She was admitted for further evaluation of the possible syncope. Review of past history suggested several months of intermittent neck pain. After a computed tomography (CT) scan of the head had been obtained and interpreted as normal, CT scanning and polytomography of the neck were carried out (Figures 2, 3, and 4). These studies confirmed the presence of a block vertebra and showed that the upper portion of the block was composed of a sagittally cleft vertebra. Also apparent was a focus of sclerotic bone at the left C5-6 uncovertebral joint. Thoracic and lumbosacral x-rays were normal, as was a renal ultrasound. Audiometry was unremarkable. An electroencephalogram showed some two dozen epileptogenic discharges occurring bilaterally and diffusely with a
168
SCHLITT
ET AL.
CLINICAL IMAGING VOL. 13, NO. 2
incorporation of that structure, or both, is unknown. The embryologic anatomy suggests the spectrum of the Klippel-Feil deformity in extrauterine life, ranging from a pair of fused cervical vertebrae to a block vertebra extending from the base of the skull to the thoracic spine associated with &ES vertebral anomalies. The second, coexisting, anomaly in this patient is that of a butterfly vertebrae (Figemres 2 and 4). This defect is felt to QCCUI between the third and sixth week of gestation (25, IS,)_ Developing vertebral bodies have two lateral chondrification centers that normally fuse. If one fails to develop completely, a hemivertebra results. Failure of the two centers to fuse, however, results in the formation of a butterfly vertebrae. This has been attributed embryologically to persistence of either the notocord or the ventrodorsal extension of the perichordal sheath, or to failure of the notochord to separate from ectoderm or endoderm. The absence of a normal disk between the FIGURE 2. Anteroposterior polytomogram of cervical spine. The upper segment of the block vertebra is a butterfly vertebra.
FIGURE 1. Lateral cervical spine film on admission showing block vertebra at C4-5.
frontal emphasis. Hypothyroidism, anemia, and mitral valve prolapse were discovered as well.
DISCUSSION A complex segmentation anomaly of the cervical vertebrae composed of a butterfly vertebra fused to the next segment does not appear to have been previously reported. The developmental processes that are the basis for such anomalies occur in the embryo between 25 and 60 days gestational age and span the phases of segmentation, membrane formation, and chondrification (2, 3, 5, 8-14). The anomaly in this report is one comprising elements of both a failure of segmentation and a failure of fusion. The Klippel-Feil anomaly arises during the eighth week of intrauterine life and represents persistence of the nearly solid cartilaginous vertebral column of that period (Figure 1). Whether it is due to failure of the intervertebral disk to form, or to ossification and
FIGURE 3. CT scan of the cervical spine. covertebral joint at C5-6 is clerotic (arrow).
The left un-
FIGURE 4. CT scan of the upper segment of the block vertebra showing the appearance of the butterfly vertebra.
170
SCHLITT ET AL.
two vertebrae may be a clue in this regard; the disk is presumably derived from the notochord and therefore separation of the centra by perichordal tissue must be favored. The stance of the patient’s head is of interest. Her husband noted that the tilt of the chin to one side was a recent development. It is suspected that the patient is developing the osteoarthritic changes that are prone to occur with congenital or iatrogenic fusions. The CT scan and polytomography revealed the presence of mild rotatory scoliosis as well as a definite, early focus of osteoarthritis in the region of the pedicle at C5-CS on the left (Figure 3). The findings of hypothyroidism and mitral valve prolapse cannot necessarily be related to the spinal anomaly. Cardiac problems in patients with KlippelFiel are usually dextrocardia or ventricular septal defects. Endocrine problems have not been reported in association with the Klippel-Fiel deformity (Z-8). However, that other organ systems are affected with the Klippel-Feil deformity is well known; one of the causes of death of Klippel and Feil’s original case was “nephritis,” which may well have been partly due to a renal malformation. A search of the rest of the spine by x-ray, ultrasonography of the kidneys, and audiometry in our patient was not rewarding. This anomaly has been named the butterfly-block vertebra to indicate the similarity to previously reported isolated vertebral anomalies. This combination of anomalies has not been reported previously and is of interest because of the two different times in development at which the failures of fusion and segmentation occurred. The importance of this anomaly is to reemphasize that spinal deformities may be asymptomatic for long periods, but when discovered they demand evaluation not only of the spine but also of other body systems that may have been affected during embryogenesis.
CLINICAL IMAGING VOL. 13, NO. 2
REFERENCES 1. Brown MW, Templeton AW, Hodges FJ. The incidence of acquired and congenital fusions in the cervical spine. AM J Roentgen01 1964;92:1255-1259. 2. Gray SW, Romaine CB, Skandalakis JE. Congenital fusion of the cervical vertebrae. Surg Gynec Obstet 1964;118:373-385. 3. McElfresh E, Winter 1973;56:353-357.
R. Klippel-Feil
syndrome.
Minn
4. Dolan KD. Developmental abnormalities of the cervical below the axis. Rad Clin North Am 1977;15:167-175.
Med spine
5. Epstein BS. The Spine, A Radiological Text and Atlas. Fourth edition. Philadelphia: Lee & Febiger Publishers, 1976, pp. 175-182, 188-90. 6. Hensinger RN, Lang JE, MacEwen GD. Klippel-Feil syndrome. A constellation of associated anomalies. J Bone Joint Surg 1974;56A:1246-1253. 7. Morrison SG, Perry LW, Scott LP. Congenital brevicollis (Klippel-Feil syndrome] and cardiovascular abnormalities. Am J Dis Child 1968;115:614-620. PD. Klippel-Feil Syndrome, Congenital Malfor0. Pizzutillo mations, The Cervical Spine, edited by the Cervical Spine Research Society. Philadelphia: J.B. Lippincott Company, 1973, pp. 174-187. abnormalities of spinal cord and 9. Lonstein JE. Developmental vertebral column, Spinal Deformities and Neurological Dysfunction, edited by SN Chou and EL Seljeskog. New York: Raven Press, 1978, pp. 42-52. 10. Schmorl G, Junghanns H. Congenital anomalies of the spine. In The Human Spine in Health and Disease. New York: Grune & Stratton, 1959, pp. 24-59. 11. Lemier RJ, Loeser JD, Leech RW, Ellsworth CA. Normal and Abnormal Development of the Human Nervous System. Hagerstown, MD: Harper & Row Publishers, 1975. 12. McRae DL. The significance of abnormalities of the cervical spine. Am J Roentgen01 Rad Ther Nucl Med 1960;84:3-25. 13. Moore KL. The Developing Human. Second edition. Philadelphia: WB Saunders, 1977, pp. 45-80. 14. Roaf R. Embryology, development and anatomy of the spine. In Spinal Deformities. Philadelnhia: 1.B. Liouincott Comnanv, _ _ _ 197?, pp. 6-20. I
_-
15. de Graaf RJ, Matricall B, Hamburger HL. Butterfly Clin Neurol Neurosurg 1982;84:163-169. 16. Muller F, O&hilly R, Benson vertebral anomalies as illustrated Anat 1986;149:157-169.
vertebra.
DR. The early origin of by a butterfly vertebra. J
CERVICAL BUTI’ERFLY-BLOCK
167
VERTEBRA
A CASE REPORT MICHAEL SCHLITT, MD, PETER J. DEMPSEY, AND R. KENT ROBINSON, MD
A new type of block vertebml malformation is described. A &‘-year-old woman presented after an akinetic seizure. Routine cervical spine films, obtained because of a recent history of abnormal head posture, disclosed a vertebral anomaly. Computed tomogmphy and conventional polytomography revealed that the lesion was composed of a butterfly vertebm as the upper portion of a pair of nonsegmented vertebme. Vertebral fusion and segmentation anomalies am reviewed and compared with the specific features of this case. KEY WORDS:
Butterfly vertebra; Embryology; IUip,pel-Feil syndrome; Spine Congenital vertebral abnormalities ,are common. The Klippel-Feil syndrome, an abnormality of segmentation defined as two or more congenitally fused cervical vertebra, may occur as frequently as in 1% of spines (l-3). This spinal abnormality is often asymptomatic per se; frequently, associated anomalies in other systems may prove more important to the individual patient (2-8). Anomalies of fusion are less frequently seen and are most commonly manifest as hemivertebrae (4, 9, 10). In contrast to the Klippel-Feil syndrome, asymmetric fusion defects often cause problems directly related to spinal deformity (5). Symmetric fusion defects leading to butter-
From the Department of Neurosurgery, University of South Alabama (M.S.), the Department of Radiology, Knollwood Park Hospital (P.J.D.), and the Department of Neurology, University of South Alabama (R.K.R.). Address reprint requests to: Dr. Michael Schlitt, 714 Mastin, USAMC, 2451 Fillingim St., Mobile, AL 36617. Received September 1988. 0 1989 by Elsevier Science Publishing Co.. Inc. 655 Avenue of the Americas, New York, NY 10010 0899/7071/89/$3.50
MD,
fly or sagittally cleft vertebrae, however, can be asymptomatic. Recently, a 42-year-old woman was admitted with a new onset of seizures. Routine radiographs disclosed a cervical spinal abnormality not previously described that was confirmed by further studies. CASE HISTORY A 42-year-old right-handed woman had been working in her garden on April 5, 1986. She began to feel hot and light-headed and went into the house. Five minutes later she was found by her husband slumped over the sink. No incontinence or tonicclonic movements were seen. She quickly regained consciousness, had no postictal confusion, and was brought to the emergency room. Neurologic examination at the time of admission was normal. However, her husband noted that she had held her head with the chin tilted to the left for some months, for which reason cervical spine x-rays were obtained (Figure 1) that showed a block vertebra composed of the fourth and fifth cervical vertebrae. She was admitted for further evaluation of the possible syncope. Review of past history suggested several months of intermittent neck pain. After a computed tomography (CT) scan of the head had been obtained and interpreted as normal, CT scanning and polytomography of the neck were carried out (Figures 2, 3, and 4). These studies confirmed the presence of a block vertebra and showed that the upper portion of the block was composed of a sagittally cleft vertebra. Also apparent was a focus of sclerotic bone at the left C5-6 uncovertebral joint. Thoracic and lumbosacral x-rays were normal, as was a renal ultrasound. Audiometry was unremarkable. An electroencephalogram showed some two dozen epileptogenic discharges occurring bilaterally and diffusely with a
168
SCHLITT
ET AL.
CLINICAL IMAGING VOL. 13, NO. 2
incorporation of that structure, or both, is unknown. The embryologic anatomy suggests the spectrum of the Klippel-Feil deformity in extrauterine life, ranging from a pair of fused cervical vertebrae to a block vertebra extending from the base of the skull to the thoracic spine associated with &ES vertebral anomalies. The second, coexisting, anomaly in this patient is that of a butterfly vertebrae (Figemres 2 and 4). This defect is felt to QCCUI between the third and sixth week of gestation (25, IS,)_ Developing vertebral bodies have two lateral chondrification centers that normally fuse. If one fails to develop completely, a hemivertebra results. Failure of the two centers to fuse, however, results in the formation of a butterfly vertebrae. This has been attributed embryologically to persistence of either the notocord or the ventrodorsal extension of the perichordal sheath, or to failure of the notochord to separate from ectoderm or endoderm. The absence of a normal disk between the FIGURE 2. Anteroposterior polytomogram of cervical spine. The upper segment of the block vertebra is a butterfly vertebra.
FIGURE 1. Lateral cervical spine film on admission showing block vertebra at C4-5.
frontal emphasis. Hypothyroidism, anemia, and mitral valve prolapse were discovered as well.
DISCUSSION A complex segmentation anomaly of the cervical vertebrae composed of a butterfly vertebra fused to the next segment does not appear to have been previously reported. The developmental processes that are the basis for such anomalies occur in the embryo between 25 and 60 days gestational age and span the phases of segmentation, membrane formation, and chondrification (2, 3, 5, 8-14). The anomaly in this report is one comprising elements of both a failure of segmentation and a failure of fusion. The Klippel-Feil anomaly arises during the eighth week of intrauterine life and represents persistence of the nearly solid cartilaginous vertebral column of that period (Figure 1). Whether it is due to failure of the intervertebral disk to form, or to ossification and
FIGURE 3. CT scan of the cervical spine. covertebral joint at C5-6 is clerotic (arrow).
The left un-
FIGURE 4. CT scan of the upper segment of the block vertebra showing the appearance of the butterfly vertebra.
170
SCHLITT ET AL.
two vertebrae may be a clue in this regard; the disk is presumably derived from the notochord and therefore separation of the centra by perichordal tissue must be favored. The stance of the patient’s head is of interest. Her husband noted that the tilt of the chin to one side was a recent development. It is suspected that the patient is developing the osteoarthritic changes that are prone to occur with congenital or iatrogenic fusions. The CT scan and polytomography revealed the presence of mild rotatory scoliosis as well as a definite, early focus of osteoarthritis in the region of the pedicle at C5-CS on the left (Figure 3). The findings of hypothyroidism and mitral valve prolapse cannot necessarily be related to the spinal anomaly. Cardiac problems in patients with KlippelFiel are usually dextrocardia or ventricular septal defects. Endocrine problems have not been reported in association with the Klippel-Fiel deformity (Z-8). However, that other organ systems are affected with the Klippel-Feil deformity is well known; one of the causes of death of Klippel and Feil’s original case was “nephritis,” which may well have been partly due to a renal malformation. A search of the rest of the spine by x-ray, ultrasonography of the kidneys, and audiometry in our patient was not rewarding. This anomaly has been named the butterfly-block vertebra to indicate the similarity to previously reported isolated vertebral anomalies. This combination of anomalies has not been reported previously and is of interest because of the two different times in development at which the failures of fusion and segmentation occurred. The importance of this anomaly is to reemphasize that spinal deformities may be asymptomatic for long periods, but when discovered they demand evaluation not only of the spine but also of other body systems that may have been affected during embryogenesis.
CLINICAL IMAGING VOL. 13, NO. 2
REFERENCES 1. Brown MW, Templeton AW, Hodges FJ. The incidence of acquired and congenital fusions in the cervical spine. AM J Roentgen01 1964;92:1255-1259. 2. Gray SW, Romaine CB, Skandalakis JE. Congenital fusion of the cervical vertebrae. Surg Gynec Obstet 1964;118:373-385. 3. McElfresh E, Winter 1973;56:353-357.
R. Klippel-Feil
syndrome.
Minn
4. Dolan KD. Developmental abnormalities of the cervical below the axis. Rad Clin North Am 1977;15:167-175.
Med spine
5. Epstein BS. The Spine, A Radiological Text and Atlas. Fourth edition. Philadelphia: Lee & Febiger Publishers, 1976, pp. 175-182, 188-90. 6. Hensinger RN, Lang JE, MacEwen GD. Klippel-Feil syndrome. A constellation of associated anomalies. J Bone Joint Surg 1974;56A:1246-1253. 7. Morrison SG, Perry LW, Scott LP. Congenital brevicollis (Klippel-Feil syndrome] and cardiovascular abnormalities. Am J Dis Child 1968;115:614-620. PD. Klippel-Feil Syndrome, Congenital Malfor0. Pizzutillo mations, The Cervical Spine, edited by the Cervical Spine Research Society. Philadelphia: J.B. Lippincott Company, 1973, pp. 174-187. abnormalities of spinal cord and 9. Lonstein JE. Developmental vertebral column, Spinal Deformities and Neurological Dysfunction, edited by SN Chou and EL Seljeskog. New York: Raven Press, 1978, pp. 42-52. 10. Schmorl G, Junghanns H. Congenital anomalies of the spine. In The Human Spine in Health and Disease. New York: Grune & Stratton, 1959, pp. 24-59. 11. Lemier RJ, Loeser JD, Leech RW, Ellsworth CA. Normal and Abnormal Development of the Human Nervous System. Hagerstown, MD: Harper & Row Publishers, 1975. 12. McRae DL. The significance of abnormalities of the cervical spine. Am J Roentgen01 Rad Ther Nucl Med 1960;84:3-25. 13. Moore KL. The Developing Human. Second edition. Philadelphia: WB Saunders, 1977, pp. 45-80. 14. Roaf R. Embryology, development and anatomy of the spine. In Spinal Deformities. Philadelnhia: 1.B. Liouincott Comnanv, _ _ _ 197?, pp. 6-20. I
_-
15. de Graaf RJ, Matricall B, Hamburger HL. Butterfly Clin Neurol Neurosurg 1982;84:163-169. 16. Muller F, O&hilly R, Benson vertebral anomalies as illustrated Anat 1986;149:157-169.
vertebra.
DR. The early origin of by a butterfly vertebra. J