Propriospinal myoclonus with life threatening tonic spasms as paraneoplastic presentation of breast cancer

The role of the laboratory in the expanding field of neuroimmunology: Autoantibodies to neural targets

Accelerated identification of autoantibodies associated with previously idiopathic neurological disease has provided insights into disease mechanisms, enhanced understanding of neurological function, and opportunities for improved therapeutic interventions. The role of the laboratory in the expanding field of neuroimmunology is critical as specific autoantibody identification provides guidance to clinicians in diagnosis, prognosis, tumor search strategies, and therapeutic interventions. The number of specific autoantibodies identified continues to increase and newer testing strategies increase efficiencies in the laboratory and availability to clinicians. The need for broadly targeted efficient testing is underscored by the variability in clinical presentation and tumor associations attributable to a specific autoantibody, and conversely the various autoantibody specificities that can be the cause of a given clinical presentation. While many of the antineural antibodies were first recognized in the setting of neoplastic disease, idiopathic autoimmune neurological disease in the absence of underlying tumor is increasingly recognized. Appropriation of therapeutic modalities used to treat autoimmune disease to treat these autoantibody mediated neurological diseases has improved patient outcomes. Interaction between clinicians and laboratorians is critical to our understanding of these diseases and optimization of the clinical benefits of our increasing knowledge in neuroimmunology.

Propriospinal myoclonus: clinical reappraisal and review of literature

OBJECTIVE

Propriospinal myoclonus (PSM) is a rare disorder with repetitive, usually flexor arrhythmic brief jerks of the trunk, hips, and knees in a fixed pattern. It has a presumed generation in the spinal cord and diagnosis depends on characteristic features at polymyography. Recently, a historical paradigm shift took place as PSM has been reported to be a functional (or psychogenic) movement disorder (FMD) in most patients. This review aims to characterize the clinical features, etiology, electrophysiologic features, and treatment outcomes of PSM.

METHODS

Re-evaluation of all published PSM cases and systematic scoring of clinical and electrophysiologic characteristics in all published cases since 1991.

RESULTS

Of the 179 identified patients with PSM (55% male), the mean age at onset was 43 years (range 6-88 years). FMD was diagnosed in 104 (58%) cases. In 12 cases (26% of reported secondary cases, 7% of total cases), a structural spinal cord lesion was found. Clonazepam and botulinum toxin may be effective in reducing jerks.

CONCLUSIONS

FMD is more frequent than previously assumed. Structural lesions reported to underlie PSM are scarce. Based on our clinical experience and the reviewed literature, we recommend polymyography to assess recruitment variability combined with a Bereitschaftspotential recording in all cases.

Clinical diagnosis of propriospinal myoclonus is unreliable: an electrophysiologic study

Propriospinal myoclonus is a rare movement disorder that is hypothesized to arise from a spinal generator that transmits activity up and down the spinal cord via long propriospinal pathways. Polymyography is mandatory for the diagnosis, but the typical electrophysiological pattern described for propriospinal myoclonus has been also found in patients with psychogenic axial jerks, supported by the presence of a Bereitschaftspotential (BP; from German, "readiness potential," also called the premotor potential). We evaluated polymyographic findings in 65 patients referred to us with a clinical diagnosis of propriospinal myoclonus and also looked for the presence of the BP, as detected by jerk-locked back-averaging. At clinical reassessment by a movement disorder specialist, nearly one-half of the patients had clinical clues suggestive of a psychogenic cause of the jerks. Electrophysiological studies were carried out on all 65 patients. Polymyography findings revealed an incongruent electromyographic pattern for propriospinal myoclonus in 84.6% of patients and the presence of the BP in 86.1% of the entire cohort. When taking into account either the presence of BP and/or incongruence of polymyographic features, all patients, including the approximately 50% clinically diagnosed as organic propriospinal myoclonus by a movement disorder expert, had strong neurophysiological evidence for a psychogenic origin of their jerks. The clinical distinction of propriospinal myoclonus from psychogenic axial jerks is unreliable. This is the largest cohort of patients with axial jerks reported so far and we suggest that most of the patients with a clinical picture that clinically resembles propriospinal myoclonus are likely to be psychogenic.

Propriospinal myoclonus in a child

A 6-year-old girl was experiencing repetitive involuntary and massive jerks immediately involving limbs and trunk. The first motor events appeared approximately at 1 year old and only 5 months after a back trauma. Myoclonus became progressively more frequent and more violent, causing episodes of falls. Neurological examination showed jerks characterized by upper limb abduction, lower limb abduction, and head-body hyperextension. Apart from these motor events, the neurological examination was normal. The results of vitamin B(12) and folate, antinuclear antibody, anti-DNA, anti-Tiroglobulin, anti-thyroid peroxidase antibody, lupus anticoagulant, anti-cardiolipin antibody, rheumatoid factor, and C3 and C4 were unexceptional. Electroencephalography and brain and spinal magnetic resonance imaging were unremarkable. Electromyographic records with surface electrodes showed that duration of myoclonic jerks was ranging from 100 to 300 ms. We thought she had propriospinal myoclonus because of presence of the spreading through the shoulder, upper limbs, and lower limbs in addition to thoracolumbar paraspinal muscles.

Steroid-responsive paraneoplastic demyelinating neuropathy and myelopathy associated with breast carcinoma

Paraneoplastic myeloneuropathy has rarely been reported with breast cancer. We report the case of a 59-year-old woman who presented with a peripheral neuropathy and cranial involvement and later developed a myelopathy. The neuropathy was found to be electrophysiologically and histologically demyelinating in nature. Magnetic resonance imaging studies failed to identify any structural brain or spinal cord abnormalities. The patient was diagnosed with breast carcinoma 4 months after initial presentation and underwent resective surgery, radiotherapy, and hormonotherapy. Paraneoplastic antibodies (anti-Hu, anti-Yo, anti-Ri, anti-CV2, anti-Ma, and anti-amphiphysin) were all negative. Her condition did not progress further after cancer treatment. Partial neurologic improvement occurred with oral steroid therapy, with subsequent deterioration on treatment withdrawal.

Propriospinal myoclonus: Utility of magnetic resonance diffusion tensor imaging and fiber tracking

Propriospinal myoclonus (PSM) is a rare movement disorder characterized by involuntary spinal-generated muscular jerks that spread rostrally and caudally to other spinally innervated muscles. Most patients have no clear etiology, and conventional MRI of the spinal cord is generally normal. Here we report the use of magnetic resonance diffusion tensor imaging (DTI) and fiber tracking to detect tract-specific abnormalities in a patient with propriospinal myoclonus. As the patient had the fragile-X premutation and antithyroid antibodies, spinal cord DTI abnormalities may be related to these conditions. Tract-specific analysis may provide new insights into the pathophysiology of propriospinal myoclonus.