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Foot drop following brain lesion
ELSEVIER
Neurology
FOOT DROP FOLLOWING H. Eskandary,
BRAIN LESION
M.D., A. Hamzei, M.D., and M.T. Yasamy, M.D.
Departments of Neurosurgery, Neurology, and Psychiatry, Bahonar Hospital, Kerman University of Medical Sciences,
Eskandary
H, Hamzei
A, Yasamy
MT. Foot drop following brain
lesion. Surg Neurol 199.5;43:89-90.
Six cases of foot drop following brain lesions in patients suffering from parasagittal pathology are reported. In three of these cases, foot drop was the first clinical presentation. The commonly held view that foot drop is mainly due to peripheral or spinal pathology, though correct, may lead to unnecessary investigation and delayed diagnosis. KEY WORDS
Foot drop, brain, parasagittal.
Foot drop and spinal dystrophy
has been known to occur in peripheral motor neuron lesions and in muscular [l-4]. Parasagittal lesions have been
stated to cause foot drop in at least one textbook [4,7]. In our clinical experience during a 6-year interval, we encountered six cases of foot drop appearing in patients with brain lesions.
CASE REPORTS CASE
1
An IS-year-old girl sought help from an orthopedic surgeon for difficulty in walking. She was referred to us for steppage gait with no other complaint. Neurological examination revealed foot drop, extensor plantar reflex and ankle clonus without sensory loss. Electromyogram (EMG) and nerve conduction velocity were not contributory. Myelography was normal. One month later the patient complained of progressive headache. Brain computed tomography (CT) scan revealed a hyperdense lesion with distinct margins and contrast enhancement, located in the right deep parasagittal region. The patient was lost to follow-up.
CASE
0 1995 by Elsevfer Science Inc. 655 Avenue of the Americas, New York, NY 10010
2
A 33-year-old man was referred with left hemiparesis of 5 months’ duration. Neurological examination revealed left hemiparesis and weakness of left ankle and toe dorsiflexion. CT scan showed a right parasagittal hyperdense lesion. He gained good neurological improvement after surgery. Pathological finding was meningioma. CASE
3
A 14year-old girl was admitted with fever, headache, and vomiting. Neurological examination revealed no abnormality, except papilledema in both eyes. CT scan showed a hypodense lesion in the right parasagittal region. The patient underwent operation with a diagnosis of brain abscess. After surgery, she developed a left spastic foot drop; there was considerable improvement after 3 weeks. CASE
4
A 55-year-old man suffering from foot drop was referred to a neurologist. Neurological examination revealed ankle clonus with no sensory loss. Myelography was negative. Over 2 weeks the patient developed a left hemiparesis. CT revealed a deep right parasagittal lesion. Pathological examination revealed a grade 2 astrocytoma. CASE
5
A 2S-year-old woman presented with left foot drop and hemiparesis. Neurological examination revealed extensor plantar reflex, decreased touch and pain sensation, moderate muscle weakness on the left side, and bilateral lower limb hyperreflexia. Brain CT was normal. Brain and spinal cord MRl were obtained. The spinal cord was intact on brain magnetic resonance imaging (MRf), there were multiple demyelinating plaques in the periventricular region. CASE
Address reprint requests to: H. Eskandary, M.D., Department of Neurosurgery, Bahonar Hospital, Kerman University of Medical Sciences, Kerman, Iran. Received January 20, 1994; accepted May 12, 1994.
Kerman, Iran
6
A lo-year-old boy was referred to the emergency room for head injury. On his first visit he was suffering from right foot drop, hemiparesis, hyper0090-3019/95/$9.50 SSDI 0090-3019(94)00094-7
90
Surg Neurol 1995;43:89-90
reflexia, and extensor plantar reflex. Skull X-ray showed a parietal depressed fracture and parietooccipital linear fracture. CT revealed a parietal depressed fracture and cerebral contusion. On discharge he was improved in all respects except for some residual weakness of plantar dorsiflexion.
DISCUSSION Most clinicians facing a case of foot drop first think of peripheral nerve lesion. This is true in most cases, but it would be erroneous to generalize this way of thinking [4,6,8]. In our six cases the cause of foot drop was parasagittal pathology; in half of them foot drop was the first clinical presentation. The cerebral cause of foot drop will not be missed in head injury patients, or in those with clinical features clearly indicating cerebral pathology. However, there remains a group of foot drop patients with central pathology but with a clinical presentation resembling peripheral causes of foot drop but with upper motor neuron features which may be differentiated if there is Babinski sign or hyperactive ankle jerk [7]. This type has been called “spastic foot drop” by Guthrie et al [4]. In our patients the lesion occupied a more or less parasagittal location. Brain localization studies of motor cortex using electrostimulating technique have precisely determined the somatotopic localization of ankle and toe in the parasagittal region [2,5]. Our experience justifies a thorough workup of all patients referred with foot drop. This should include both an upper and a lower motor neuron investigation. Investigation for the central cause of foot drop is especially indicated in cases where it is associated with Babinski sign, hyperreflexia, or headache. REFERENCES 1. Adams RD, Victor M. Principles of neurology. 3rd ed. New York: McGraw-Hill 1985:90-6. 2. Eberhard EF. Motor function of cerebral cortex: In: Patton HD, ed. Textbook of physiology. Vol 1. 1989; 608-31.
Eskandary
et al
3. Goldner JC, Thomas JE. Foot drop. Am Fam Physician 1969;17:51-9. 4. Guthrie BL, Ebersold MJ, Scheithauer BW. Neoplasms of the intracranial meninges. In: Youmans ER, ed. Neurological surgery. Vol 5. Philadelphia: WB Saunders, 1990;3250-315. 5. Noback CR, Demarest RJ. The human nervous system. 3rd ed. New York: McGraw-Hill 1981;482-525. 6. Sabin HJ, Lidov HE, Kendall BE, Symon L. LhermitteDuclos disease (dysplastic gangliocytoma): a case re port with CT and MRI. Acta Neurochir (Wien) 1988;93: 149-53. 7. Talbert OR. General methods of clinical examination. In: Youmans ER, ed. Neurological surgery. 3rd ed. Vol 1. Philadelphia: W.B. Saunders 1990: 17. 8. Van Langenhove M, Pollefliet A, Vanderstraeten G. A retrospective electrodiagnostic evaluation of foot drop in 303 patients. Electromyogr Clin Neurophysiol 1989;29:145-52.
COMMENTARY
The most common causes of foot drop are lesions of the fifth lumbar root or the peroneal nerve. The fifth lumbar root may be involved by disc, metastatic lesions, neurofibroma, and meningioma. The common peroneal nerve is commonly injured where it swings around the head of the fibula to the anterior aspect of the leg. Frequent causes of injury to the common peroneal nerve include pressure on the peroneal nerve during surgery or sleep, tight plaster casts, and obstetrical stirrups. Risk of injury is increased in emaciated patients. The nerve may be primarily involved in diabetic neuropathy. Fractures of the upper end of the fibula may also injure the common peroneal nerve. The authors point out that foot drop may also occur with brain lesions. Lesions in the parasagittal region near the motor strip for the leg area may produce foot drop. A cerebral lesion should be suspected in patients who have either a Babinski sign or increased deep tendon reflexes. Headache is a further clue that a central cause exists. Daniel B. Hier, M.D. Chicago, Illinois
Neurology
FOOT DROP FOLLOWING H. Eskandary,
BRAIN LESION
M.D., A. Hamzei, M.D., and M.T. Yasamy, M.D.
Departments of Neurosurgery, Neurology, and Psychiatry, Bahonar Hospital, Kerman University of Medical Sciences,
Eskandary
H, Hamzei
A, Yasamy
MT. Foot drop following brain
lesion. Surg Neurol 199.5;43:89-90.
Six cases of foot drop following brain lesions in patients suffering from parasagittal pathology are reported. In three of these cases, foot drop was the first clinical presentation. The commonly held view that foot drop is mainly due to peripheral or spinal pathology, though correct, may lead to unnecessary investigation and delayed diagnosis. KEY WORDS
Foot drop, brain, parasagittal.
Foot drop and spinal dystrophy
has been known to occur in peripheral motor neuron lesions and in muscular [l-4]. Parasagittal lesions have been
stated to cause foot drop in at least one textbook [4,7]. In our clinical experience during a 6-year interval, we encountered six cases of foot drop appearing in patients with brain lesions.
CASE REPORTS CASE
1
An IS-year-old girl sought help from an orthopedic surgeon for difficulty in walking. She was referred to us for steppage gait with no other complaint. Neurological examination revealed foot drop, extensor plantar reflex and ankle clonus without sensory loss. Electromyogram (EMG) and nerve conduction velocity were not contributory. Myelography was normal. One month later the patient complained of progressive headache. Brain computed tomography (CT) scan revealed a hyperdense lesion with distinct margins and contrast enhancement, located in the right deep parasagittal region. The patient was lost to follow-up.
CASE
0 1995 by Elsevfer Science Inc. 655 Avenue of the Americas, New York, NY 10010
2
A 33-year-old man was referred with left hemiparesis of 5 months’ duration. Neurological examination revealed left hemiparesis and weakness of left ankle and toe dorsiflexion. CT scan showed a right parasagittal hyperdense lesion. He gained good neurological improvement after surgery. Pathological finding was meningioma. CASE
3
A 14year-old girl was admitted with fever, headache, and vomiting. Neurological examination revealed no abnormality, except papilledema in both eyes. CT scan showed a hypodense lesion in the right parasagittal region. The patient underwent operation with a diagnosis of brain abscess. After surgery, she developed a left spastic foot drop; there was considerable improvement after 3 weeks. CASE
4
A 55-year-old man suffering from foot drop was referred to a neurologist. Neurological examination revealed ankle clonus with no sensory loss. Myelography was negative. Over 2 weeks the patient developed a left hemiparesis. CT revealed a deep right parasagittal lesion. Pathological examination revealed a grade 2 astrocytoma. CASE
5
A 2S-year-old woman presented with left foot drop and hemiparesis. Neurological examination revealed extensor plantar reflex, decreased touch and pain sensation, moderate muscle weakness on the left side, and bilateral lower limb hyperreflexia. Brain CT was normal. Brain and spinal cord MRl were obtained. The spinal cord was intact on brain magnetic resonance imaging (MRf), there were multiple demyelinating plaques in the periventricular region. CASE
Address reprint requests to: H. Eskandary, M.D., Department of Neurosurgery, Bahonar Hospital, Kerman University of Medical Sciences, Kerman, Iran. Received January 20, 1994; accepted May 12, 1994.
Kerman, Iran
6
A lo-year-old boy was referred to the emergency room for head injury. On his first visit he was suffering from right foot drop, hemiparesis, hyper0090-3019/95/$9.50 SSDI 0090-3019(94)00094-7
90
Surg Neurol 1995;43:89-90
reflexia, and extensor plantar reflex. Skull X-ray showed a parietal depressed fracture and parietooccipital linear fracture. CT revealed a parietal depressed fracture and cerebral contusion. On discharge he was improved in all respects except for some residual weakness of plantar dorsiflexion.
DISCUSSION Most clinicians facing a case of foot drop first think of peripheral nerve lesion. This is true in most cases, but it would be erroneous to generalize this way of thinking [4,6,8]. In our six cases the cause of foot drop was parasagittal pathology; in half of them foot drop was the first clinical presentation. The cerebral cause of foot drop will not be missed in head injury patients, or in those with clinical features clearly indicating cerebral pathology. However, there remains a group of foot drop patients with central pathology but with a clinical presentation resembling peripheral causes of foot drop but with upper motor neuron features which may be differentiated if there is Babinski sign or hyperactive ankle jerk [7]. This type has been called “spastic foot drop” by Guthrie et al [4]. In our patients the lesion occupied a more or less parasagittal location. Brain localization studies of motor cortex using electrostimulating technique have precisely determined the somatotopic localization of ankle and toe in the parasagittal region [2,5]. Our experience justifies a thorough workup of all patients referred with foot drop. This should include both an upper and a lower motor neuron investigation. Investigation for the central cause of foot drop is especially indicated in cases where it is associated with Babinski sign, hyperreflexia, or headache. REFERENCES 1. Adams RD, Victor M. Principles of neurology. 3rd ed. New York: McGraw-Hill 1985:90-6. 2. Eberhard EF. Motor function of cerebral cortex: In: Patton HD, ed. Textbook of physiology. Vol 1. 1989; 608-31.
Eskandary
et al
3. Goldner JC, Thomas JE. Foot drop. Am Fam Physician 1969;17:51-9. 4. Guthrie BL, Ebersold MJ, Scheithauer BW. Neoplasms of the intracranial meninges. In: Youmans ER, ed. Neurological surgery. Vol 5. Philadelphia: WB Saunders, 1990;3250-315. 5. Noback CR, Demarest RJ. The human nervous system. 3rd ed. New York: McGraw-Hill 1981;482-525. 6. Sabin HJ, Lidov HE, Kendall BE, Symon L. LhermitteDuclos disease (dysplastic gangliocytoma): a case re port with CT and MRI. Acta Neurochir (Wien) 1988;93: 149-53. 7. Talbert OR. General methods of clinical examination. In: Youmans ER, ed. Neurological surgery. 3rd ed. Vol 1. Philadelphia: W.B. Saunders 1990: 17. 8. Van Langenhove M, Pollefliet A, Vanderstraeten G. A retrospective electrodiagnostic evaluation of foot drop in 303 patients. Electromyogr Clin Neurophysiol 1989;29:145-52.
COMMENTARY
The most common causes of foot drop are lesions of the fifth lumbar root or the peroneal nerve. The fifth lumbar root may be involved by disc, metastatic lesions, neurofibroma, and meningioma. The common peroneal nerve is commonly injured where it swings around the head of the fibula to the anterior aspect of the leg. Frequent causes of injury to the common peroneal nerve include pressure on the peroneal nerve during surgery or sleep, tight plaster casts, and obstetrical stirrups. Risk of injury is increased in emaciated patients. The nerve may be primarily involved in diabetic neuropathy. Fractures of the upper end of the fibula may also injure the common peroneal nerve. The authors point out that foot drop may also occur with brain lesions. Lesions in the parasagittal region near the motor strip for the leg area may produce foot drop. A cerebral lesion should be suspected in patients who have either a Babinski sign or increased deep tendon reflexes. Headache is a further clue that a central cause exists. Daniel B. Hier, M.D. Chicago, Illinois