Amyotrophic Lateral Sclerosis

A 65-year-old man presented with progressive weakness and wasting of right hand for 2 years followed by proximal weakness of right upper limb for 1½ years. He also had distal weakness of right lower limb for 1 year and bulbar symptoms with difficulty in swallowing and speaking for 2 months. He had a history of muscle cramps and fasciculations in his extremities. He also experienced fatigue and had weight loss of around 3 kg over the past few months. He had no sensory, cerebellar, extrapyramidal, autonomic, behavioral, or memory disturbances. There was no positive family history. On examination, the eye movements were normal; there was an atrophic, weak flabby tongue with fasciculations and slow movements. There was a mixed type of dysarthria, and the jaw jerk was brisk. There was asymmetric wasting of small muscles of hands, predominantly of the thenar eminence (ape thumb deformity). The shoulder girdle muscles were wasted. Minipolymyoclonus was prominently present. He had proximal and distal weakness of all four limbs with spasticity and exaggerated tendon reflexes. There was no Babinski’s sign, and abdominal reflexes were elicited. Sensory system examination was normal. He had a pure motor syndrome with a clinical diagnosis of amyotrophic lateral sclerosis (ALS). Blood investigations like hemogram, renal, liver, and thyroid function tests were normal. Nerve conduction study showed a decrease in compound muscle action potential (CMAP) amplitudes with normal distal latency and velocity in tested nerves of upper and lower limbs. Sensory conductions were normal. Electromyography (EMG) confirmed a diagnosis of ALS by showing changes of denervation and partial re-innervation in sampled muscles of the upper and lower limbs and the cranial musculature. Workup for other secondary causes like endocrinopathy, paraproteinemia, and neoplasm was negative. The patient fulfilled the criteria for a clinically definite case of ALS by modified Airlie House El Escorial criteria.