Inflammatory radiculoneuropathy in an ALS4 patient with a novelSETXmutation: Figure 1

Amyotrophic lateral sclerosis 4 (ALS4), a rare form of autosomal dominant juvenile-onset ALS characterised by slow progression and sparing of bulbar and respiratory muscles,1 2 results from missense mutations in the senataxin ( SETX ) gene.3 This study reports the clinical pathology of a male Japanese ALS4 patient carrying a novel mutation in the SETX gene who presented with coexistent inflammatory radiculoneuropathy. Slight delays in early development resulted in the patient beginning to walk at 1.5 years. He was prone to falls and had suffered from pes cavus since childhood. At 35 years of age, the patient presented with difficulty walking. One year later he found it difficult to fully extend his fingers and this was exacerbated over the following 3 months. Nerve conduction studies revealed asymmetric demyelinating patterns (median nerve motor conduction velocity: right 29 m/s, left 53 m/s). Subsequently, the patient developed a neurogenic bladder. Intravenous immunoglobulin therapy (20 g/day for 5 days) resulted in mild improvement in muscle weakness (one point on the manual muscle test) and in the amplitude of compound motor action potentials for the median (right 1.982 mV to 3.362 mV, left 1.342 mV to 2.062 mV) and right ulnar nerve (6.064 mV to 8.296 mV). At 37 years of age, the patient developed progressive distal weakness and sensory disturbances in the right forearm and medial thigh. Following two courses of intravenous methylprednisolone (1 g/day for 3 days; steroid pulse therapy) and subsequent oral prednisolone treatment (50 mg/day with gradual tapering), sensory impairment and muscle weakness both improved. Thereafter, the patient underwent repeated steroid pulse therapy when muscle weakness became worse. At 41 years of …