Beneficial effects of Rituximab in patients with anti-MAG (myelin-associated glycoprotein) neuropathy: case reports.

Anti-myelin-associated glycoprotein (MAG) neuropathy is a primary demyelinating sensorimotor polyneuropathy that can be very debilitating and is known to be resistant to treatment. There are only a few conflicting reports on the effect of Rituximab in anti-MAG neuropathy. We present three patients who improved remarkably with Rituximab infusions. Until the safety and efficacy of this drug are determined in larger controlled studies, use of Rituximab should be limited to patients with significant neurologic deficits.

Asymmetric phenotype associated with rare myelin protein zero mutation.

Myelin protein zero (MPZ) mutations cause demyelinating neuropathies that range from severe neonatal to milder adult forms. We report a 36-year-old man who developed weakness of his left little finger adduction 3 years earlier. The weakness progressed to his other limbs. Examination revealed mildly high-arched feet with asymmetric weakness of ulnar-innervated muscles (left > right) and asymmetric weakness of peroneal-innervated muscles (right > left). Motor nerve conduction velocities ranged from 18.4 to 24.4 m/s in the upper extremities and from 14.8 to 22.7 in the lower extremities. Left median partial motor conduction block was noted at the forearm segment. Genetic testing demonstrated MPZ mutation with ARG98HIS amino acid change. The patient's father is a 68-year-old man who was asymptomatic and who was noticed to have high-arched feet and asymmetric leg muscle atrophy and weakness (right > left). The patient's 2-year-old son is "clumsy" with history of neonatal laryngomalacia. He has flat feet, areflexia, and difficulty standing on individual right versus left leg. The patient's paternal grandfather had high-arched feet and hearing loss. We conclude that ARG98HIS MPZ mutation may cause hereditary and relatively mild and asymmetric demyelinating sensorimotor polyneuropathy.

Patient with amyloidoma of the ulnar nerve and salivary glands.

Amyloidomas of the peripheral nervous system have been reported rarely. We describe a patient with a history of localized amyloidosis of the salivary glands who presented a few years later with paresthesias of her left medial arm, forearm, and fifth digit. A mass affecting the left ulnar nerve was confirmed by MRI studies. It was excised and proven on pathological examination to be an amyloidoma. The benign course of this patient's illness is consistent with localized amyloidosis affecting two different organs.

Myotonic dystrophy type 1 presenting with ventilatory failure.

OBJECTIVE: To report a series of patients with adult onset myotonic dystrophy type 1 (DM1) in whom the presenting symptom was ventilatory failure. BACKGROUND: Ventilatory failure is a common complication of DM1 and may be a presenting symptom in the setting of anesthesia or surgery, but it is not known to be a heralding manifestation. METHOD: Case series. RESULTS AND DISCUSSION: Three adults developed dyspnea leading to ventilatory failure, with no cardiac or pulmonary causes identified. Case 1 required intubation for ventilator support and was sedated with propofol. There was no clinical myotonia, and electromyography (EMG) demonstrated brief runs of myotonic discharges. Examination 3 weeks later off propofol revealed percussion myotonia, and EMG evidence of long runs of myotonic discharges. Genetic testing confirmed the diagnosis of DM1. Case 2 had cataracts and ptosis but no known diagnosis of DM and no previous neurological impairments. Case 3 was previously neurologically asymptomatic but her son had congenital DM1. The diagnosis was confirmed by EMG in cases 2 and 3, and both patients were managed with bilevel ventilation (BIPAP). CONCLUSION: Myotonic dystrophy type 1 should be considered in the differential diagnosis of acute ventilatory failure in adults.