Nerve rootlets to be sectioned for spasticity resolution in selective dorsal rhizotomy.

BACKGROUND: The goal of this study is to confirm the efficacy of the protocol for selective dorsal rhizotomy (SDR). In this protocol, rootlets to be sectioned are selected by palpable responses elicited by intraoperative electrical stimulation, without detailed electromyographic classifications. METHODS: Thirty-six children with spasticity due to cerebral palsy underwent SDR according to our protocol. Priority was given to sectioning rootlets that showed palpable clonic or bilateral responses, which were considered abnormal, over sectioning rootlets that merely had hyperactive responses to intraoperative stimulation. The results of intraoperative monitoring and sectioning amount were analyzed by physical evaluation. RESULTS: Significant improvements were obtained in passive range of motion and muscle tone of the lower extremities. The total percentages of rootlets with abnormal and hyperactive responses at L3 and S1 were bilaterally correlated with preoperative spasticity of the hip adductors and the plantar flexors, respectively. When rootlets with hyperactive responses were excluded from the correlation analysis, no bilateral correlation was observed. From the correlation analyses between the improvement in the physical evaluation and the amount of nerve sectioned, it was concluded that a greater improvement in muscle tone in all examined muscles, except the hamstrings, could be obtained if larger amounts of nerve roots were sectioned. CONCLUSION: The number of rootlets with palpable abnormal and hyperactive responses elicited by intraoperative stimulation reflects the preoperative spasticity of multiple muscles. This implies that only selecting rootlets with palpable responses can be reliable. Because more sectioning leads to better spasticity resolution, our protocol should be reviewed to increase the percentage of rootlets sectioned with hyperactive responses, especially for innervated levels of severely affected muscles.

Neurologic manifestations of compressive radiculopathy of the first thoracic root.

Neurologic deficits in the first thoracic (T1) root distribution are uncommon and not easily defined. Myotomal charts indicate that distal arm and hand muscles receive significant contributions from both the C8 and T1 roots. A patient with focal T1 radiculopathy is presented who demonstrated motor axon loss isolated to the abductor pollicis brevis muscle. This finding provides another source of evidence that the abductor pollicis brevis is the primary T1 motor structure in the upper extremity, improving precision in clinical and electromyographic diagnosis.

The dropped head plus syndrome: quantitation of response to corticosteroids.

Severe neck extensor weakness causes the dropped head syndrome and is a disabling symptom of many specific disorders. When a diagnosis cannot be established, it has been considered a manifestation of a restricted noninflammatory myopathy. A 44-year-old man presenting with dropped head and subsequent severe limb weakness did not respond to a first trial of corticosteroids but responded well to a subsequent prolonged trial of azathioprine followed by prednisone. The decision to persist with the second trial of treatment was prompted by documented sequential increases in lean body and muscle mass, and an improvement in the quantitative myometry score which preceded clinically obvious improvement. While mechanical damage to overstretched cervical paraspinal muscles is thought to preclude a response to treatment, cases of unexplained dropped head syndrome may merit consideration of prolonged immunosuppressant treatment.

Cervical rib and median sternotomy-related brachial plexopathies: a reassessment.

OBJECTIVE: The objective of this study was to identify electrodiagnostic and anatomic distinctions between true neurogenic thoracic outlet syndrome and median sternotomy-related brachial plexopathy, in reference to the pattern of abnormality of the medial antebrachial cutaneous sensory nerve conduction study (NCS) response. BACKGROUND: Neurogenic thoracic outlet syndrome and sternotomy-related brachial plexopathy are both lower trunk brachial plexopathies, but their clinical and electrodiagnostic presentations are distinct. The anatomic differences distinguishing these disorders from each other, and from other lower trunk brachial plexopathies, have not been defined. METHODS: We compared the medial antebrachial cutaneous sensory nerve action potential amplitude with the median motor, ulnar motor, and ulnar sensory NCS amplitudes in 10 patients with neurogenic thoracic outlet syndrome and in 14 patients with sternotomy-related brachial plexopathy. RESULTS: In the 10 patients with neurogenic thoracic outlet syndrome, the medial antebrachial cutaneous amplitude was most affected, followed in decreasing order of involvement by the median motor, ulnar sensory, and ulnar motor amplitudes. Conversely, in the 14 patients with sternotomy-related brachial plexopathy, the ulnar sensory and motor amplitudes were the most affected responses. Medial antebrachial cutaneous NCS changes closely paralleled median motor response changes. CONCLUSIONS: The medial antebrachial cutaneous sensory response is sensitive in the diagnosis of neurogenic thoracic outlet syndrome. Our data suggest that medial antebrachial cutaneous nerve fibers are closely associated anatomically at the T1 root level with median motor fibers innervating the thenar muscles. Neurogenic thoracic outlet syndrome shows predominant damage in the T1 distribution, whereas sternotomy-related brachial plexopathy shows predominant damage in the C8 distribution, suggesting that these lesions are localized at the level of the anterior primary rami of the cervical roots, and not in the lower trunk of the brachial plexus.

L5 radiculopathy with reduced superficial peroneal sensory responses: intraspinal and extraspinal causes.

Thirteen patients were retrospectively identified with the electrodiagnostic pattern of combined L5 radiculopathy by needle electrode examination, and abnormality of the superficial peroneal nerve (SPN) sensory nerve action potential (SNAP) amplitude. To have combined L5-derived sensory and motor axon loss, lesions must be localized at or distal to the L5 dorsal root ganglion (DRG), but also proximal to the sacral plexus. Six patients had evidence of an active intraspinal canal (ISC) lesion, 3 had diabetes, and 4 had nonspecific causes. The ISC localization in at least 6 of our cases is counter to the commonly held electrodiagnostic dogma that L5 radiculopathy spares the SPN SNAP, but recent anatomic studies confirm the ISC location of up to 40% of L5 DRG. Thus loss of the SPN SNAP does not exclude ISC lesions.

Paraneoplastic neuromuscular syndromes.

Although paraneoplastic syndromes are rare, a number of well- defined, neuromuscular paraneoplastic syndromes have been described and their pathophysiology listed. Many different malignancies have been associated with these syndromes, but small-cell lung cancer is the most common. Features shared by these conditions include onset of the underlying malignancy, rapid progression, severe disability, and the potential for some improvement, owing to treatment of the cancer. This article discusses Lambert-Eaton myasthenic syndrome, motor neuron disorders, peripheral neuropathies, and disorders of continuous muscle fiber activity, such as Stiffman syndrome.

Angiotropic large-cell lymphoma with peripheral nerve and skeletal muscle involvement: early diagnosis and treatment.

Angiotropic large-cell lymphoma is a disorder characterized by an intravascular proliferation of malignant lymphoid cells. We present a patient with polyradiculoneuropathy, myelopathy, and myopathy diagnosed by peripheral nerve and muscle biopsy, who was treated and remains in stable neurologic condition.

Cervical radiculopathies: comparison of surgical and EMG localization of single-root lesions.

To identify the various electrodiagnostic (EDX) patterns of C-5, C-6, C-7, and C-8 cervical radiculopathy, we compared 50 cases of surgically proven solitary-root lesions with their preoperative EDX patterns. We excluded patients with polyradiculopathy, myelopathy, and previous surgery. We classified EDX studies as abnormal only by the needle electrode examination, and only by the demonstration of fibrillation potentials (either the positive sharp wave or the biphasic spike form). Seven patients (14%) had C-5 radiculopathy, nine (18%) had C-6, 28 (56%) C-7, and six (12%) C-8. With C-5, C-7, and C-8 radiculopathies, changes were relatively stereotyped, with involvement of the spinati,deltoid, biceps, and brachioradialis with C-5; the pronator teres, flexor carpi radialis, triceps, and anconeus with C-7; and the first dorsal interosseous, abductor digiti minimi, abductor pollicis brevis, flexor pollicis longus, and extensor indicis proprius with C-8. The root lesion with the most variable presentation was C-6--in half the patients, the findings were similar to C-5 radiculopathies, except that the pronator teres tended to be involved, whereas in the other half, the findings were identical to those with C-7 radiculopathies.

Obturator mononeuropathy caused by pelvic cancer: six cases.

OBJECTIVE: To report the clinical and pelvic CT findings in six patients with obturator mononeuropathy caused by cancer. DESIGN: A clinical case series of six patients followed for 2 months to 10 years (one patient lost to follow-up). SETTING: Three referral centers. PATIENTS: Three men and three women, ages 52 to 81 years. Three patients had transitional cell carcinoma of the bladder, and one patient each had pelvic papillary carcinoma, carcinoma of unknown origin, and lymphoma. MAIN RESULTS: In each patient, symptoms of obturator mononeuropathy were the sole presenting sign of new or recurrent pelvic cancer. Three patients had ipsilateral leg edema in addition to the typical sensory and motor findings of obturator mononeuropathy. Tumor sites detected on pelvic CT that correlated with obturator nerve compression or infiltration, singly or in combination, included the posterolateral wall of the upper pelvis or midpelvis, the anterior wall of the lower pelvis, and the external obturator and pectineus muscles extrinsic to the bony pelvis. Antineoplastic treatment provided symptomatic relief in four patients. CONCLUSIONS: Pelvic CT or MRI should be performed to exclude pelvic tumor in patients with obturator mononeuropathy if there is no temporal association with pelvic trauma or intra-abdominal, pelvic, or hip surgery.

Common focal mononeuropathies and their electrodiagnosis.

Common focal mononeuropathies can be produced by compression, entrapment, crush, stretch, and transection. Injuries resulting from acute or chronic repetitive external pressure produce compressive neuropathy, whereas chronic distortion or angulation of the nerve from an internal source produces entrapment neuropathy. Electrodiagnostic techniques used in the electromyographic laboratory include nerve conduction studies and the needle electrode examination. Measurement of distal latency, amplitude, conduction velocity, and identification of focal conduction block may help in the localization of focal mononeuropathies. The needle electrode examination gives further information about the distribution of nerve damage, the activity and chronicity of axon loss, and can sometimes date the onset of injury. Basic clinical features and electrodiagnostic patterns are discussed for median, ulnar, radial, and peroneal neuropathies. Differential diagnosis is provided, and illustrative cases are presented.

Childhood peroneal neuropathy from bone tumors.

Nontraumatic childhood peroneal mononeuropathy is uncommon and should initiate a search for surgically correctable causes. In 3 children, 2 age 12 years and 1 age 13 years, unilateral footdrop developed over a few days to a month. Electrodiagnostic findings demonstrated lesions with maximal or exclusive involvement of the deep peroneal nerve. Radiologically, bony exostoses were identified at or near the fibular head in each patient. In 2 patients, the lesions were clinically occult. An osteochondroma was removed from each patient and 2 patients had excellent clinical recoveries.

Hypertrophic mononeuritis clinically presenting with painful legs and moving toes.

A 40-year-old woman presented with progressive lower leg pain and spontaneous toe movement. The EMG showed a posterior tibial nerve mononeuropathy and continuous myokymic discharges in posterior tibial-innervated muscles. The MRI revealed a markedly enlarged posterior tibial nerve. Toe movements and myokymia were unaffected by the proximal transection of the lesion but ceased abruptly when the distal end of the fusiform "tumor" was resected, suggesting that spontaneous electrical foci may have been located along the nerve lesion. The markedly enlarged nerve segment contained edematous, swollen fascicles with marked Schwann cell onion-bulb lesions and angiocentric, lymphocytic, and lymphofollicular infiltration. This nerve lesion is an example of a newly recognized entity called hypertrophic mononeuritis.

AAEE case report #19: ischemic monomelic neuropathy.

A case study of a 50-year-old man who awakened from aortobifemoral bypass graft surgery with painful burning and numbness of the left foot is reported. Angiography showed embolic occlusion of the left popliteal artery proximal to the knee. Nerve conduction studies performed 1 year after occlusion showed loss or severe reduction of distal left sensory and motor amplitudes, and needle electrode examination showed fibrillation potentials in foot and distal leg muscles. The findings were felt to represent the result of acute ischemic nerve damage in the left leg. The clinical and electromyographic features of this entity will be described and comparisons will be drawn to experimental ischemic neuropathy and diabetic neuropathy.

Response of CSF IgG to steroids in an 18-month-old with chronic inflammatory polyradiculoneuropathy.

During recovery from a upper respiratory infection, an acquired chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) developed in a previously healthy 18-month-old girl. The CIDP followed a monophasic course and left her severely quadriparetic. One year after her neurologic deficit had stabilized, the cerebrospinal fluid (CSF) IgG synthesis rate was markedly elevated, and oligoclonal bands were identified in her CSF, suggesting ongoing inflammation. Her electromyogram (EMG) and nerve biopsy were consistent with a severe acquired segmental demyelinating polyradiculoneuropathy. A course of corticosteroid therapy resulted in dramatic, sustained, clinical and electromyographic improvement, normalization of CSF IgG synthesis rate, and disappearance of the oligoclonal bands. We are not aware of any previous reports that correlate serial measurements of CSF IgG synthesis rate and oligoclonal bands with clinical and electromyographic responses to corticosteroids in a child with acquired CIDP. We suggest that these CSF parameters are potentially useful in demonstrating active inflammation in cases of acquired CIDP even after clinical stabilization of neurologic deficits, predicting response to therapy, and monitoring resolution of the pathologic process.

Systemic vasculitis in association with human immunodeficiency virus infection.

Fourteen cases of vasculitis associated with human immunodeficiency virus infection have thus far been described. Five of these cases may be classified as angiocentric immunoproliferative disorders, including benign lymphocytic angiitis, lymphomatoid granulomatosis, and angiocentric lymphoma. We report a case of benign lymphocytic angiitis of T cell lineage. Extensive studies found no evidence of viral antigens in the inflammatory infiltrates, and immunologic evaluation of the pathologic lesions revealed the infiltrating cells to be predominantly CD3+, CD8+, CD4-. A significant number of these lymphocytes demonstrated a deletion of T cell antigen receptor determinants. We believe that in certain cases of human immunodeficiency virus disease, there occurs a spectrum of lymphoproliferative disorders with angiocentric features that lead to the clinical picture of systemic necrotizing vasculitis. Clinicians should be aware of this association.

Acute infection with the human immunodeficiency virus (HIV) associated with acute brachial neuritis and exanthematous rash.

Clinical descriptions of acute or primary infection with the human immunodeficiency virus (HIV) are rare. Among cases previously reported, most describe an acute illness resembling infectious mononucleosis. We describe the case of a 32-year-old homosexual man with an acute illness associated with strong serologic evidence of a primary infection with HIV. This case illustrates two new clinical features: an acute, bilateral brachial neuritis, and a vesicular, pustular exanthematous and enanthematous rash. Studies of HIV-related serologic results show differential sensitivities for enzyme-linked immunosorbent assay, Western blot, immunofluorescence, and viral antigen techniques in the acute phase of HIV infection. There appears to be significant clinical heterogeneity of the acute phase of HIV infection.

Superficial peroneal nerve conduction studies for electromyographic diagnosis.

A new standardized surface technique for conduction studies of the superficial peroneal nerve was developed and applied to 35 normal subjects and 63 patients with peroneal mononeuropathies, lumbar radiculopathies, sciatic neuropathies, lumbosacral plexopathies, or peripheral neuropathies. The response amplitude was greater than 5 microV and the response peak latency was less than 4.1 msec in all normal subjects; however, 8.6% of normal subjects had at least one unelicitable superficial peroneal nerve response (6% of all limbs tested). These data were compared with those of previous studies. Although this technique did not improve the diagnosis of peroneal neuropathy, it did distinguish lumbosacral plexopathy and sciatic neuropathy from L5 radiculopathy and served as a second, easily approachable, sensory conduction study of the leg.

Spinal cord infarction: another cause of "lumbosacral polyradiculopathy".

An elderly woman with leg weakness and sensory loss had fibrillation potentials in her legs and at multiple lumbosacral levels of paraspinal muscles. Clinical and myelographic studies showed occlusion of an anterior spinal artery due to an arteriovenous malformation of the spinal cord. EMG aided in the diagnosis and localization of this anterior spinal cord lesion.