A 21-year-old male patient presented with progressive weakness and atrophy of both upper and lower limbs of 8-10-year duration. Symptoms first appeared in the upper limbs at the age of 14 years, as asymmetrical weakness of both upper limbs. The weakness did not affect daily activities so the patient neglected the symptoms till relatives described thinning of both upper limbs and loss of muscle bulk. The patient also had a history of occasional tingling in both of his hands which was left unattended. The local hospital could not detect any ailment and the patient was discharged with few medications. Over the next few years, the patient started having difficulty in gripping and holding objects. He found it difficult to ride a bicycle and write. In addition, he started feeling clumsiness of both lower limbs and found it difficult to run and play football. There were no bladder and bowel abnormalities. He was taken to the nearest medical college, where suspicion of motor neuron disease was made by preliminary investigations. Chest and cervico-dorsal plain radiographs, cervical MRI, brain CT and MRI, and infection screening including TB were all negative, so no conclusive diagnosis was made. The patient's weakness and atrophy involved both upper and lower limbs. The symptoms continued to progress for the next two years and the patient was unable to lift heavy objects or ride a bicycle but he was able to walk unassisted. There was occasional back pain. By the age of 17 years, the patient started feeling better and was able to walk much better and ride a bicycle again. He attempted to play football, but his limbs continued to be very atrophic and thin and did not improve with time. Since the last two years from his 19th birthday onwards, the patient again noted worsening of symptoms and accelerated deformity and weakness of both lower limbs. Back pain has increased, both hands and forearm appear even more atrophic and the patient can barely walk or grip things at the time of presentation.
The boy had normal speech and higher mental processes and neurological examination revealed an attentive, conscious and oriented individual. Higher cranial nerves examinations were within normal limits. Examination of the upper limbs revealed forearm, interosseous, thenar, and hypothenar muscular atrophy and weakness (Figures 1-3).
Examining the lower limbs indicated more extensive calf and thigh muscular atrophy. Clawing with the Hallux Valgus deformity was observed on both feet (Figure 4). Both the upper and lower limbs had normal deep tendon responses. Deep and superficial sensory examinations were normal. Gait and coordination were both typical. He didn't have any tremors, fasciculations, uncontrollable movements, or unusual perspiration. No bladder or bowel involvement was found. Respiratory rate was normal without any breathing difficulty. Electromyography (EMG) and nerve conduction velocity (NCV) test findings were suggestive of latency in the Median and Ulnar nerve conductions with no recording at the wrist for the right Median nerve. Similarly, there was latency seen in bilateral Posterior Tibial and Common Peroneal nerve conductions. Sensory studies were within normal limits. Such recordings were again suggestive of selective motor axon degenerative pathology, hence an early diagnosis of generalized motor neuron disease like amyotrophic lateral sclerosis (ALS) was made but lack of respiratory and abdominal muscle involvement and a brief period of spontaneous recovery and relative lesser involvement of other nerve roots made the diagnosis questionable.
MRI of the brain was normal. MRI of the cervical spine with screening of other regions was normal (Figure 5 and Figure 6), but a cervico-thoracic flexion MRI revealed forward migration of the posterior wall of the dura mater indenting the spinal cord from C7-D7 levels with prominent posterior epidural space with fat and flow voids. On contrast MRI there was prominent homogenous posterior epidural enhancement (Figure 7). Routine blood test, rheumatoid profile, thyroid screening and Vit D levels were within normal levels.
Based on these findings a diagnosis of atypical Hirayama disease involving cervico-thoracic region was made. A neurosurgeon's opinion was sought and duroplasty was advised. The patient refused surgery and is on regular follow-up. Although there has been no improvement in the patient's condition but there is also no further deterioration. The patient is at times able to walk without support. He is supplemented with neurovitamins like methylcobalamine, B1 and B6. The trial with steroids did not show any additional improvement so was discontinued. The patient continues physiotherapy and occupational rehabilitation and is relatively doing well.