Mutational analysis of glycyl-tRNA synthetase (GARS) gene in Hirayama disease.

Sporadic juvenile muscular atrophy of the distal upper extremity or Hirayama's disease (HD) and autosomal dominant motor distal neuronopathy/axonopathy (CMT2D/dSMA-V), produced by glycyl-tRNA synthetase (GARS) gene mutations, share some clinical features including: young age of onset, predilection for the distal upper extremity, asymmetry, sparing of proximal muscles and unusual cold sensitivity. However, incomplete penetrance of GARS gene mutations may account for apparently non-familial cases. In order to inquire whether GARS gene mutations are associated with HD we studied seven patients fulfilling the clinical and electrodiagnostic criteria for HD.

Evoked potential studies in the antiphospholipid syndrome: differential diagnosis from multiple sclerosis.

Background: The CNS manifestations of the antiphospholipid syndrome (APS) can mimic multiple sclerosis both clinically and radiologically.

Objective: To compare evoked potential studies in APS patients and patients with multiple sclerosis with similar neurological disability.

Methods: 30 APS patients with CNS manifestations and 33 patients with definite multiple sclerosis and similar neurological disability underwent studies of visual evoked potentials (VEP), somatosensory evoked potentials (SSEP) in the upper and lower limbs (UL, LL), and sympathetic skin responses (SSR) in the upper and lower limbs.

Acute neuropathy mimicking porphyria induced by aminolevulinic acid during photodynamic therapy.

An 82-year-old man developed severe, acute, predominantly motor polyneuropathy, signs of autonomic involvement, and skin changes following aminolevulinic acid (ALA) administration. The compound was used as a prodrug for photodynamic therapy of Barrett's esophagitis. Changes were observed in various parameters of the heme pathway.

R-R interval variation in Parkinson's disease and multiple system atrophy.

Objective: To investigate whether the cardiac R-R interval variation (RRIV) is of value in differentiating patients with Parkinson's disease (PD) from multiple system atrophy (MSA).

Background: RRIV assessment is a simple procedure, reflecting mainly vagal efferent activity. Reduced RRIV was reported in MSA.

Electrophysiologic evaluation of upper motor neuron involvement in amyotrophic lateral sclerosis.

Background: The demonstration of upper motor neuron (UMN) dysfunction in patients with amyotrophic lateral sclerosis (ALS) with predominantly lower motor neuron (LMN) signs is clinically sometimes difficult.

Methods: We analyzed the possible role of F and H waves in the diagnosis of UMN dysfunction in 36 patients with different clinical forms of ALS and 20 controls. In both lower limbs we evaluated F-wave persistence and the F/M ratio of tibial nerves, Hmax/Mmax ratio, vibratory and recurrent (paired) inhibition of the H-reflex.