Sensory Polyneuropathy Associated with Pyridoxine Overdose

Pyridoxine deficiency and excess have both been implicated as causes of peripheral neuropathy. A 74-year-old man presented with paresthesia in both legs that first appeared 2 months previously. A nerve conduction study revealed axonal sensory polyneuropathy. He had consumed 100 milligrams of pyridoxine every day for 1 year, in the form of vitamin tablets. His blood levels of vitamin B6 were markedly elevated to above 250 nmol/L. This case indicates that the consumption of high-dose pyridoxine can cause sensory polyneuropathy.

Concurrent Demyelinating Polyneuropathy Associated with Recurrent Cervical Myelitis

No abstract available.

Diagnostic Sensitivity and Specificity of Residual Latency and Terminal Latency Index in the Diagnosis of Carpal Tunnel Syndrome

BACKGROUND: Conventional nerve conduction studies (NCS) are used in the diagnosis of carpal tunnel syndrome (CTS). The median terminal latency index (TLI) and median residual latency (RL) are parameters calculated to identify abnormalities in distal segments of the median motor nerve. The objective of this study was to determine the sensitivity and specificity of TLI and RL together with NCS in the diagnosis of CTS. METHODS: This prospective study involved 83 hands of 47 patients with suspected CTS. Conventional NCS were performed using Oh's method. Control data were obtained from the 68 hands of 40 healthy volunteers. The diagnostic sensitivity and specificity of TLI and RL were calculated and compared with those of conventional NCS. We divided the CTS patients into four groups based on their electrophysiological severity, and compared the TLI and RL values between these groups. RESULTS: TLI and RL were 0.20+/-0.03 (mean+/-SD) and 3.62+/-0.90, respectively, in the patients, while the corresponding values, in the healthy control, were 0.29+/-0.03 and 2.08+/-0.30. The sensitivities of TLI and RL in diagnosing CTS were 75.9% and 86.3%, respectively. Compared with median motor terminal latency, the sensitivities of TLI and RL in diagnosing CTS was found to be higher. Moreover, the diagnostic sensitivities of TLI and RL were significant better for the severe group than for the mild and moderate severity group. CONCLUSIONS: We conclude that measuring TLI and RL of the median nerve may increase the sensitivity in diagnosing CTS and also provide information about its electrophysiological severity.

Diagnostic Sensitivity and Specificity of Residual Latency and Terminal Latency Index in the Diagnosis of Carpal Tunnel Syndrome

BACKGROUND: Conventional nerve conduction studies (NCS) are used in the diagnosis of carpal tunnel syndrome (CTS). The median terminal latency index (TLI) and median residual latency (RL) are parameters calculated to identify abnormalities in distal segments of the median motor nerve. The objective of this study was to determine the sensitivity and specificity of TLI and RL together with NCS in the diagnosis of CTS. METHODS: This prospective study involved 83 hands of 47 patients with suspected CTS. Conventional NCS were performed using Oh's method. Control data were obtained from the 68 hands of 40 healthy volunteers. The diagnostic sensitivity and specificity of TLI and RL were calculated and compared with those of conventional NCS. We divided the CTS patients into four groups based on their electrophysiological severity, and compared the TLI and RL values between these groups. RESULTS: TLI and RL were 0.20+/-0.03 (mean+/-SD) and 3.62+/-0.90, respectively, in the patients, while the corresponding values, in the healthy control, were 0.29+/-0.03 and 2.08+/-0.30. The sensitivities of TLI and RL in diagnosing CTS were 75.9% and 86.3%, respectively. Compared with median motor terminal latency, the sensitivities of TLI and RL in diagnosing CTS was found to be higher. Moreover, the diagnostic sensitivities of TLI and RL were significant better for the severe group than for the mild and moderate severity group. CONCLUSIONS: We conclude that measuring TLI and RL of the median nerve may increase the sensitivity in diagnosing CTS and also provide information about its electrophysiological severity.

Intracranial Vasospasm without Intracranial Hemorrhage due to Acute Spontaneous Spinal Subdural Hematoma

Spontaneous spinal subdural hematoma (SDH) is very rare. Furthermore, intracranial vasospasm (ICVS) associated with spinal hemorrhage has been very rarely reported. We present an ICVS case without intracranial hemorrhage following SDH. A 41-year-old woman was admitted to our hospital with a complaint of severe headache. Multiple intracranial vasospasms were noted on a brain CT angiogram and transfemoral cerebral angiography. However, intracranial hemorrhage was not revealed by brain MRI or CT. On day 3 after admission, weakness of both legs and urinary incontinence developed. Spine MRI showed C7~T6 spinal cord compression due to hyperacute stage of SDH. After hematoma evacuation, her symptoms gradually improved. We suggest that spinal cord evaluation should be considered in patients with headache who have ICVS, although intracranial hemorrhage would not be visible in brain images.