Acute Spinal Rigidity

Abstract

Focal or segmental rigidity is a rare presentation of spinal cord pathology. In the absence of other clinical features, comprehensive spinal imaging should be performed first to exclude structural (developmental or neoplastic), inflammatory, demyelinating, or vascular myelopathies. Focal or segmental rigidity as the principal sign of a neurological disorder is more commonly associated with immune-mediated encephalomyelopathies such as the stiff person syndrome (SPS), or when other neurological features are present, progressive encephalomyelitis with rigidity and myoclonus (PERM). While these conditions are also rare, neuroimmunological discoveries have revealed the association of antiglutamic acid decarboxylase (GAD) antibodies with SPS and antiglycine receptor antibodies with PERM. Rigidity in SPS and PERM is mediated through spinal mechanisms released from local spinal inhibitory control and the descending control of muscle tone from brainstem centers. This chapter presents an approach to the diagnosis and management of rigidity as the primary presenting feature of neurological illness.KeywordsFocal and segmental rigiditySpinal rigidityAlpha rigidityStiff person syndromeProgressive encephalomyelitis with rigidity and myoclonus