Movement disorders after intervertebral disc surgery: Coincidence or causal relationship?

Extended Wrist Rotation Simplified

Extended wrist rotation provides a simple clinical measure of rigidity in movement disorders. The supinator-pronator muscles of the forearm form an agonist-antagonist pair that can be isolated for diagnosis and monitoring. Patients rarely can isolate these muscles without extraordinary training and body awareness. Clinicians may find documenting the impact of the shoulder girdle, wrist, and hand movements overburdensome. A preliminary study shows that restricting the olecranon and keeping the wrist in line with the hand can provide a simple, reproducible measure of rigidity. We study a two-handed "handshake" examination and the use of a pulley-based goniometer. This preliminary analysis indicates that both offer the same observer and between-observer reliability. Two-way analysis of variance showed no statistical differences or outliers.

Spinal segmental myoclonus following spinal surgery

A 44-year-old male was admitted with L5/S1 spondylodiscitis complicated by a posterior epidural abscess that was compressing the thecal sac with severe narrowing of the canal and compression of the cauda equine. He underwent computed tomography (CT) guided drainage followed by L5/S1 decompression laminectomy and was started on a 6-week course of intravenous antibiotics with good response. He remained well and afebrile with inflammatory markers showing improvement. During this period, he developed intermittent myoclonic movements of right lower limb with severe pain over the back radiating to the gluteal region which hindered his rehabilitation potential. He was diagnosed with spinal segmental myoclonus based on clinical findings and history of recent spinal surgery. He was successfully treated with a course of clonazepam and continues to make functional improvements during his rehabilitation program.

Movement Disorders Associated With Radiotherapy and Surgical Procedures

Occasionally, movement disorders can occur following interventional procedures including but not limited to radiotherapy, dental procedures, and cardiac, cerebral and spinal surgeries. The majority of these disorders tend to be unexpected sequelae with variable phenomenology and latency, and they can often be far more disabling than the primary disease for which the procedure was performed. Owing to poor knowledge and awareness of the problem, delays in diagnosing the condition are common, as are misdiagnoses as functional movement disorders. This narrative review discusses the phenomenology, pathophysiology, and potential treatments of various movement disorders caused by interventional procedures such as radiotherapy and neurological and non-neurological surgeries and procedures.

Paroxysmal spinal hemidystonia in neuromyelitis optica

Paroxysmal dystonia occurs because of genetic or structural lesion in the basal ganglia or thalamus, and there is paucity of reporting in spinal pathology. We report a patient with paroxysmal hemidystonia admitted to a tertiary care hospital, India, and review the literature on spinal dystonia in neuromyelitis optica (NMO). A 19-year-old woman presented with recurrent visual loss and quadriparesis. She developed paroxysmal hemidystonia after 18 days of a second episode of quadriplegia, during which her muscle power improved to Grade 3. Magnetic resonance imaging (MRI) of her spine showed central T2 hyperintensity extending from C2 to C7 vertebral level, and a cranial MRI was normal. Tibial somatosensory evoked potentials were unrecordable. Aquaporin-4 antibody was positive in serum, confirming the diagnosis of NMO. Paroxysmal hemidystonia responded to carbamazepine 200 mg thrice daily. Paroxysmal dystonia may occur in a patient with myelitis and may respond to carbamazepine.

Scar Dancing Syndrome: Peripheral Trauma Induced Involuntary Hyperkinesia around Surgical Incision

Background

Peripherally induced movement disorders represent a rare and debated complication of peripheral trauma. It is difficult to determine a causal relationship between peripheral injuries and subsequent movement disorders.

Cases

Here, we introduce and characterize four patients with post-surgical scar-associated movement disorders, a peripherally-induced rippling movement disorder confined to the muscles just under a long surgical incision scar, appearing weeks to months after surgery. This novel 'scar dancing' syndrome does not spread to adjacent muscles and persists during sleep.

Conclusion

Scar dancing syndrome expands the phenotypic spectrum of peripherally induced movement disorders, in which movement disorder is confined to a long surgical incision site.

Delayed Propriospinal Myoclonus Following Dorsal Spinal Cord Surgery

Cerebral disorders are known to be associated with myoclonus, but spinal pathologies have received little attention as a causative factor in movement disorders. Propriospinal myoclonus (PSM) is a rare hyperkinetic movement disorder caused by activity of a spinal pattern generator localized in a few segments of the spinal cord, spreading to other intraspinal segments via propriospinal pathways. Majority of cases of PSM are reported as functional movement disorders. Structural lesions were found in only a small number of reported cases. We present this rare case report of a patient who developed PSM 2 years following spinal surgery, done 5 years ago for D6–D7 vertebral body collapse. To the best of our knowledge, only few cases of PSM have been reported after spinal surgery and none from India.

Spinal myoclonus: a rare presentation of cervical myelopathy

Myoclonus describes a movement disorder characterised by brief, abrupt and involuntary contractions of muscles or groups of muscles, usually associated with intracranial lesions, with limited evidence linking it to spinal pathologies. The pathophysiology of spinal myoclonus is extensive and multifactorial. Infection, intramedullary and extramedullary space-occupying lesions, trauma, vascular abnormalities, degenerative processes and cervical spondylosis have been implicated with the disease, the latter been associated with cervical stenosis with no reported cases linking it to an underlying cervical disc herniation. Although medical therapy with clonazepam, levetiracetam, valproate, tetrabenazine hydrochloride and spinal block injections has been equivocal, spinal myoclonus secondary to disc herniation requires surgical intervention. This report describes a case of segmental spinal myoclonus, secondary to a herniated cervical intervertebral disc. After corpectomy and a cage-augmented fusion technique, the myoclonic symptoms resolved. To our knowledge, this was the first report to describe the successful management of discogenic spinal myoclonus with spinal surgery.

Peripherally induced movement disorders

Peripherally induced movement disorders may be defined as involuntary or abnormal movements triggered by trauma to the cranial or peripheral nerves or roots. Although patients often recall some history of trauma before the onset of a movement disorder, determining the true relationship of the disorder to the earlier trauma is often difficult. The pathophysiology of these disorders is reviewed.

[Case of painful muscle spasm induced by thoracic vertebral fracture: successful treatment with lumbar sympathetic ganglia block]

We report a 70-year-old man, who developed painful involuntary muscle contraction of the left leg after the lumbar discectomy, which exacerbated after a vertebral fracture of Th12. This involuntary movement was accompanied with the abnormal position of left leg simulating triple flexion response, and was induced by active or passive movement of his left knee and foot joints. Several drugs including benzodiazepines and dantrolene were ineffective, although treatment with baclofen or carbamazepine was effective. These findings suggest that hyperexcitability of the anterior horn cells following the disturbance of spinal inhibitory interneurons was involved. Electophysiological studies suggested the disturbance of left lumber nerve roots. The spinal root blocks from L3 to S1 were performed, after which the painful involuntary muscle spasm was resolved. The lumbar sympathetic ganglia block was also effective; suggesting that abnormal afferent neuronal input to spinal cord was caused by the nerve root trauma which triggered the formation of secondary abnormal network in the spine. Lumbar sympathetic ganglia block should be recommended to a therapeutic option for the refractory painful muscle spasm of the leg.

Propriospinal myoclonus due to cervical disc herniation. Case report

Propriospinal myoclonus is a rare form of spinal myoclonus. In most cases the cause has remained unclear. Secondary propriospinal myoclonus has been described secondary to various disorders including trauma, tumor, and infection. Thus far, propriospinal myoclonus caused by cervical disc herniation has not been reported. In the present report, the authors describe the case of a 53-year-old man who presented with radicular symptoms of the right C-6 nerve root and myoclonic twitches predominantly affecting the abdominal muscles but spreading to adjacent muscles. The spread was triggered and enforced by certain movements. Magnetic resonance imaging studies revealed a C-6 nerve root compression at the C5-6 level on the right side but no cervical myelopathy. Electromyography studies confirmed the diagnosis of propriospinal myoclonus. After discectomy and cage-augmented fusion via an anterior approach, the myoclonic movement disorder gradually subsided. To the authors' knowledge, this is the first report on successful treatment of propriospinal myoclonus by spinal disc surgery.