Case 1 history, examination
In 2013 30 years old male patient developed a right calf muscle crampy. Already in 2014 patient developed right leg weakness, fasciculations in right leg muscles, shin atrophy, right foot drop. At that time the neurological examination revealed the muscle strength in the left limbs 5/5 points, in the right limbs 5/5 points, except for the extensors of the foot — where it was 2/5 points; amyotrophy of the right shin muscles, the absence of sensation disturbances (Fig.1). Disease progression was slow and in 2015 amyotrophy involved right thigh muscles. By the end of 2015, the patient developed fasciculations throughout the body, painful cramps and muscle weakness in the left shin. During this time, the examination revealed brisk knee reflexes, the Babinsky sign on the right side. In 2016 patient developed left leg amyotrophy, in 2017 left foot drop. In 2018 weakness involved left thigh and upper extremities.
The patient was observed in dynamics and in 2019 neurological assessment revealed restricted movements mostly in lower limbs, excessive amyotrophy of the right and left legs, but no observable amyotrophy of the upper limbs (Fig.2). Generalized fasciculations were noted. Motor examination showed excessive muscle weakness of the lower limbs more pronounced in distal part, and mild weakness of the upper limbs. Deep tendon reflexes were brisk with wide spread, pathological signs on upper limbs, Achilles reflex and Babinsky sign absent on both sides. Sensation to pinprick, vibration and proprioception were normal. There were no speech, swallowing, and breathe disturbances.
During the disease course the patient underwent MRI and EMG. In 2015 MRI of the spinal cord showed slit-like syrinx cavity and looking as dilated central canal of the thoracic spinal cord at the ThIII - ThIX vertebrae level, no Chiari malformation or other extramedullary factors predisposing to syringomyelia (Fig.3). MRI of the brain showed no pathology. In 2015 EMG showed signs of damage to the lower motor neurons of the of the lumbar and cervic spinal cord (both motor unit remodeling and denervation), and no conduction blocks. In 2016 EMG showed the negative trend of damage. Follow-up imaging in both 2016 and 2019 showed no significant changes in cavity size (Fig.4). Also the patient was tested for the titer of GM-1 and GM-2 antibodies (markers of multifocal motor neuropathy), which was low. Other laboratory tests of blood and CSF were normal.