A typical presentation of weakness and abnormal EMG findings in a patient with chronic myeloid leukemia and amyotrophic lateral sclerosis, a case report. A 35-year-old female with a seven-year history of CML and remission of imatinib presented with frequent falls. She initially developed muscle spasms and stiffness which progressed to weakness of left lower then right lower followed by left upper extremity. An answer your truncal sensory level involvement at right T2 and left C3 segment was found. Blood and CSF studies were unremarkable. MRI revealed non-specific foci of T2 flare signal hyperintensity in the bilateral subcortical white matter. Differential diagnosis included neural invasion of CML, tyrosine kinase inhibitor toxicity, and ALS. EMG showed diffused motor neuron pathology but did not have giant motor unit action potentials with reduced recruitment seen in ALS. She was treated with plasma freezes and IVIG with no improvement in symptoms. Serial nerve biopsy was scheduled however the patient suffered cardiac arrest while undergoing anesthesia and the procedure was aborted. After recovering she refused to undergo the procedure again. EMG showed low amplitude of right median left tibial and perineal motor evoked responses with borderline slow left tibial and perineal motor conduction velocities. Active denervation was found in the left upper limb, left lower limb, and mid thoracic and cervical paraspinals and in the right tongue. Active denervation was observed in four classic LS coil segments. Fossiculations were not observed. Motor unit abnormalities typical of ALS were not observed. An anterior truncal sensory level was also present in right T2 and left C3 arguing against ALS or motor neuron disease unless it reflected a co-existent other disorder. In the middle here was taken from our reference which shows the typical EMG findings with standard concentric electrode in ALS. A shows some fibs and positive sharp waves which are denervation potentials. We also see some complex repetitive discharges, fossiculation potentials, and of a muscle cramp per recruitment with SMUP, decrement of voluntary MUP, and a variation in SMUP during voluntary contraction. The progression of motor symptoms are typical of ALS although her EMG studies were not definitive. However, sensory findings are not typically found in ALS. Diffuse leptomeningeal disease from recurrence of CML and imatinib toxicity although typically sensory motor were both not excluded by the EMG. A workup of ruling out all other possible causes eventually led to the diagnosis of ALS. The atypical presentation in this case may be related to her underlying CML. Some studies have suggested that ALS is a perineoplastic syndrome and its incidence is increased in certain malignancies. ALS is a rare disease of which there is still much to be discovered. It is important to keep ALS in the differential diagnosis of patient with progressive weakness even with non-definitive EMG studies especially in patients with a history of cancer. And for our references, Lambert, Mulder, EMG studies in ALS from Mayo Clinic, 1957.

case report

weakness

EMG findings

amyotrophic lateral sclerosis

chronic myeloid leukemia