Dominant LMNA mutations can cause combined muscular dystrophy and peripheral neuropathy.

The coexistence of neurogenic and myogenic features in scapuloperoneal syndrome is rarely ascribed to a single gene. Defects in the nuclear envelope protein lamin A/C, encoded by the LMNA gene, have been shown to be associated with a variety of disorders affecting mainly the muscular and adipose tissues and, more recently, with autosomal recessive Charcot-Marie-Tooth type 2 neuropathy. This report is about a patient presenting features of myopathy and neuropathy due to a dominant LMNA mutation, suggesting that the peripheral nerve might be affected in primary LMNA myopathy. Our observations further support the marked intrafamilial and interfamilial phenotypic heterogeneity associated with lamin A/C defects.

Central nervous system superficial siderosis, headache, and epilepsy.

Almost 95 cases of superficial siderosis of the central nervous system have been reported in the literature. These patients showed a clinical syndrome characterized by ataxia, deafness, pyramidal system involvement, and mental deterioration with xanthochromic cerebrospinal fluid and neuroradiological findings of hemosiderin deposits. About 30% of the patients had headache as an accompanying symptom. In the present case report, we describe a 33-year-old man with the typical clinical features of superficial siderosis, who complained, since aged 8, of a severe recurrent frontal headache often associated with loss of consciousness occurring after at least 2 hours of pain. The MRI and CSF findings were consistent with subarachnoid bleeding. In our patient, headache due to meningeal irritation by subarachnoid blood induced seizures as a probable reflex of extreme pain. Carbamazepine and nimodipine prophylaxis dramatically reduced the frequency of headaches and seizures.

Amyloid neuropathy simulating lower motor neuron disease.

We report a 57-year-old man with progressive symmetric weakness and fasciculation affecting the legs. Electromyography revealed fibrillations and neurogenic motor unit potentials in the leg muscles. Biopsy of a motor branch of the obturator nerve revealed axonal degeneration, loss of myelinated nerve fibers, and amyloidosis with deposits of lambda light chains. At 6-month follow-up, the patient manifested sensory and autonomic symptoms, and lambda light chains were first detected in the serum. In this case, diagnosis of amyloidosis remained elusive until motor nerve biopsy.

Muscle fibre type and obstructive sleep apnea.

Muscular pharyngeal structural changes, as fibre type disproportion, have been described in patients affected by Obstructive Sleep Apnea (OSA) and in an animal experimental OSA model. The unsolved question is whether these muscular abnormalities are either secondary to a compensatory increased activity or due to a constitutionally determined reduction of slow-alpha motor neurons. In the present study Medium Pharyngeal Constrictor Muscles (MPCM) of OSA (n = 13) and non-OSA (n = 9) patients have been morphologically evaluated. In addition a needle biopsy of Vastus Lateralis Muscle (VLM) was performed in 5 randomly selected patients of each group. Our results confirmed a specific fibre type disproportion of MPCM of OSA patients compared to non-OSA ones with a type II predominance and aspecific myopathic changes such as fibrosis and central nuclei. No difference was found in the VLM of the two groups. This finding could be explained by a secondary adaptive transformation consequent to nocturnal upper airway resistance in OSA. In fact, it has been demonstrated in human muscle that heavy-resistance training may produce preferential type II fibre hypertrophy in stimulated muscle.