Chapter 48. Regional Anesthesia in the Patient with Preexisting Neurologic Disease
Which of the following describes the condition in which patients with preexisting neural compromise may become more susceptible to injury at another site when exposed to a secondary insult?
A. Acquired peripheral neuropathy
B. Central nervous system neuropathy
C. Double-crush phenomenon
D. Hereditary peripheral neuropathy
C is correct. The “double-crush phenomenon” describes the condition in which patients with preexisting neural compromise are exposed to a secondary insult resulting in additive damage from each isolated injury. Unfortunately there is paucity of data to support the association of preexisting neurologic disease and postregional anesthesia dysfunction.
A is incorrect. Acquired peripheral neuropathies are associated with trauma, toxins, or disease-related processes that result in inflammation and/or impaired blood flow.
B is incorrect. Central nervous system neuropathies include a group of disorders that affect the neurological function of the brain and/or spinal cord.
D is incorrect. Hereditary peripheral neuropathies represent a group of nerve disorders with a wide range of genotypes that typically present with gradual sensorimotor deficits over years to decades.
Which group of disorders is the most common inherited peripheral neuropathy?
A. Charcot-Marie-Tooth disease
B. Diabetic polyneuropathy
D. Hereditary neuropathy with liability to pressure palsy
A is correct. Charcot-Marie-Tooth (CMT) neuropathies are caused from mutations in more than 30 genes responsible for manufacturing neurons or the myelin sheath. CMT disorders affect approximately 1 in 2500 people making it the most common inherited neuropathy.
B is incorrect. Diabetic polyneuropathy is an acquired peripheral neuropathy that results in axonal degeneration secondary to the reduced delivery of blood, oxygen, and other essential nutrients.
C is incorrect. Entrapment neuropathy occurs when a single nerve is chronically compressed or mechanically injured at a specific location.
D is incorrect. Hereditary neuropathy with liability to pressure palsy (HNPP) is a rare inherited demyelinating peripheral neuropathy in which individuals suffer from repeated motor and sensory neuropathies following brief nerve compression or mild trauma (ie, pressure palsies).
Which of the following is the most common cause of systemic polyneuropathy?
A. Diabetic polyneuropathy
C. Guillain-Barré syndrome