Lower motor neuron disease associated with myelofibrosis

We present a patient who has signs pointing to the involvement of lower motor neurons and myelofibrosis. To our knowledge, unlike lymphoproliferative disorders, co-occurrence of myelofibrosis and lower motor neuron disease (MND) has not been reported so far. A 64-year-old male patient was admitted to our hospital with the complaint of painful cramps in his neck and forearms. On physical examination marked hepatomegaly and splenomegaly were found. On neurologic examination nasal quality of the voice and slight palatal weakness were detected. There were generalised slight weakness and atrophy in both proximal and distal muscle groups. Fasciculations were observed especially in forearm muscles and it was observed that he had been avoiding head movements because of painful muscle cramps. Deep tendon reflexes were hypoactive. Nerve conduction studies were normal. By needle electromyography, giant motor unit action potentials (amplitudes up to 8 mV), fibrillation potentials, positive sharp waves and fasciculation potentials were detected in all muscles which were investigated. A hypercellular bone marrow (100%) was determined by bone marrow biopsy. In addition to increased production of the myeloid and megakaryocytic lines, abnormal aggregation and grouping of megakaryocytes were seen. Reticular fibers were increased. He had some benefit of dyphenilhydantoin treatment given for the painful cramps in his neck and forearm muscles. Hydroxyurea treatment was started for myelofibrosis. Six months later, his general condition was better, and the painful cramps were completely resolved. No marked deterioration has been detected in neurologic examination and electromyography for 1 year.