Hee Kyu Kwon

Ultrasonography of Median Nerve and Electrophysiologic Severity in Carpal Tunnel Syndrome

Objective To investigate the correlation of the ultrasonographic wrist-to-forearm median nerve area ratio (WFR) and cross sectional area of median nerve at the wrist (CSA-W) to the electrophysiologic severity in patients with carpal tunnel syndrome (CTS). Method One hundred and ten wrists electrophysiologically graded as mild, moderate, and severe CTS and 38 healthy controls underwent ultrasonography of median nerve at the distal wrist crease and mid-forearm. WFR and CSA-W were analyzed according to the severity of CTS. Results WFR was 1.12±0.14, 1.91±0.33, 2.27±0.47 and 3.02±0.97 and the CSAs-W was 7.23±1.67 mm2, 13.51±3.72 mm2, 14.67±2.93 mm2, and 18.74±6.01 mm2 in controls, mild (n=28), moderate (n=46), and severe (n=36) CTS, respectively. CSA-W displayed significant differences between the control and the mild CTS, moderate CTS and severe CTS groups. However, there was no significant difference between mild CTS and moderate CTS groups. WFR revealed significant difference between all groups. The sensitivity and specificity of the WFR in grading the severity of CTS were higher than those of the CSA-W. Conclusion Ultrasonography is a useful complementary tool for the evaluation of CTS. Both WFR and CSA-W are highly correlated with severity grade of CTS. However, WFR is superior to CSA-W for diagnosis and grading of the severity of CTS.

Carpal Tunnel Syndrome and Peripheral Polyneuropathy in Patients with End Stage Kidney Disease

This study was designed to identify the causes of the development of carpal tunnel syndrome (CTS) associated with end stage kidney disease (ESKD). A total of 112 patients with ESKD, 64 on hemodialysis (HD) and 48 on peritoneal dialysis (PD), were enrolled. The duration of ESKD and dialysis, the site of the arteriovenous (A-V) fistula for HD, laboratory data such as blood urea nitrogen, creatinine, and beta-2-microglobulin were determined. Clinical evaluation of CTS and electrophysiological studies for the diagnosis of CTS and peripheral neuropathy were performed. The electrophysiological studies showed that the frequency of CTS was not different in the HD and PD groups (P = 0.823) and the frequency of CTS was not different in the limb with the A-V fistula compared to the contralateral limb (P = 0.816). The frequency of HD and PD were not related to beta-2-microglobulin levels, an indicator of amyloidosis. The frequency of CTS did not increase as the severity of the peripheral neuropathy and the duration of ESKD and dialysis increased (P = 0.307). The results of this study do not support that microglobulin induced amyloidosis or placement of an A-V fistula are associated with an increase in CTS.

The effect of anatomical variation of the sural nerve on nerve conduction studies.

Pyun S-B, Kwon H-K: The effect of anatomical variation of the sural nerve on nerve conduction studies. Am J Phys Med Rehabil 2008;87:438–442. Objective:To investigate the types of sural nerve formation through cadaver study, and to evaluate the relationship between anatomical variation and nerve conduction study (NCS). Design:We examined the formation of the sural nerve in 26 legs from cadavers. Sural NCS was performed in 60 legs of healthy adults to evaluate the influence of anatomical variation on NCS. Results:The sural nerve was formed by the anastomosis of the MSCN and LSCN in the calf in 20 out of 26 legs (76.9%). The sural nerve was a direct continuation of the MSCN in four (15.4%) cases, and there was no communication between the MSCN and LSCN in two cases (7.7%). The anastomoses were located in the middle and distal third of the leg in 9 and 11 out of 20 legs, respectively. Separate sensory nerve action potentials of the MSCN and LSCN were recorded in 4 out of 60 legs (6.7%) during NCS of the sural nerve, and a double peak was recorded in each of these legs. Conclusions:Because the sural nerve formation is highly variable, the possibility of anatomical variation should be considered when the sural sensory nerve action potential is of low amplitude and disproportionate to the neurologic evaluation.

Ultrasonography of palm to elbow segment of median nerve in different degrees of diabetic polyneuropathy

OBJECTIVE To identify the relationship between the ultrasonographic cross-sectional area (CSA) of the median nerve and electrophysiologic findings in diabetic patients. METHODS Sixty diabetic patients, 30 patients with carpal tunnel syndrome (CTS) and 30 healthy volunteers participated. The participants were divided into 4 groups: Control Group; Group I, diabetic patients without diabetic polyneuropathy (DPN); Group II, diabetic patients with DPN; and Group III, patients with CTS. Group II was subdivided into II-1 and II-2 according to DPN severity. The median nerve CSA was measured at 4 levels, and the wrist-to-forearm ratio (WFR) was calculated. RESULTS The median nerve CSAs were larger in Group II than in Group I and the Control Group. There were significant differences in the CSA between Group I and Group II-2 and between Group II-1 and II-2. There was no significant difference in the WFR among these groups. The CSAs at the wrist levels and WFR were significantly greater in Group III. CONCLUSIONS The median nerve CSA was greater in patients with DPN and was related to DPN severity. Diffuse increase in median nerve CSA without change in the WFR might be compatible with DPN. Ultrasonography could be applied for the diagnosis of DPN, especially in advanced cases. SIGNIFICANCE Ultrasonography might have value in the differential diagnosis of DPN and entrapment neuropathy.

Correlation between Location of Brain Lesion and Cognitive Function and Findings of Videofluoroscopic Swallowing Study

Objective To investigate whether patterns of swallowing difficulties were associated with the location of the brain lesion, cognitive function, and severity of stroke in stroke patients. Method Seventy-six patients with first-time acute stroke were included in the present investigation. Swallowing-related parameters, which were assessed videofluoroscopically, included impairment of lip closure, decreased tongue movement, amount of oral remnant, premature loss of food material, delay in oral transit time, laryngeal elevation, delay in pharyngeal triggering time, presence of penetration or aspiration, and the amount of vallecular and pyriform sinus remnants. The locations of brain lesions were classified into the frontal, parietotemporal, subcortical, medulla, pons, and cerebellum. The degree of cognitive impairment and the severity of stroke were assessed by the Mini Mental Status Examination (MMSE) and the National Institute of Health Stroke Scale (NIHSS), respectively. Results An insufficient laryngeal elevation, the amount of pyriform sinus, and vallecular space remnant in addition to the incidence of aspiration were correlated with medullary infarction. Other swallowing parameters were not related to lesion topology. Lip closure dysfunction, decreased tongue movement, increased oral remnant and premature loss were associated with low MMSE scores. A delayed oral transit time were associated with NIHSS scores. Conclusion In-coordination of the lip, the tongue, and the oropharynx were associated with the degree of cognitive impairment and the stroke severity rather than with the location of the lesion, whereas incomplete laryngeal elevation and aspiration were predominant in medullary lesions.

Sonography of the median nerve in carpal tunnel syndrome with diabetic neuropathy.

ObjectiveThe aim of this study was to determine the criteria for ultrasonographic measurement of the cross-sectional area (CSA) of the median nerve and differential diagnosis of patients with carpal tunnel syndrome (CTS) with or without diabetic polyneuropathy (DPN). DesignOne hundred eighty-seven patients were divided into five groups: healthy controls, CTS, diabetes with CTS but without DPN, DPN only, and both DPN and CTS. The CSAs of the median nerve were measured at four levels, and cutoff values to diagnose CTS with DPN were obtained. ResultsAll the CSAs were larger in the DPN group compared with those in the control group. The CSAs of the median nerve at the wrist revealed no significant differences among the groups with CTS; however, these groups demonstrated larger CSAs at the wrist and a higher wrist/forearm ratio compared with the DPN only group. The cutoff value for the CSA at the wrist that yielded the highest sensitivity and specificity was 11.6 mm. ConclusionsThe CSA of the median nerve at the wrist and the wrist/forearm ratio could be useful for diagnosing the comorbidity of CTS with DPN.

Neural substrates of lower extremity motor, balance, and gait function after supratentorial stroke using voxel-based lesion symptom mapping

IntroductionStroke impairs motor, balance, and gait function and influences activities of daily living. Understanding the relationship between brain lesions and deficits can help clinicians set goals during rehabilitation. We sought to elucidate the neural substrates of lower extremity motor, balance, and ambulation function using voxel-based lesion symptom mapping (VLSM) in supratentorial stroke patients.MethodsWe retrospectively screened patients who met the following criteria: first-ever stroke, supratentorial lesion, and available brain magnetic resonance imaging (MRI) data. MRIs of 133 stroke patients were selected for VLSM analysis. We generated statistical maps of lesions related to lower extremity motor (lower extremity Fugl-Meyer assessment, LEFM), balance (Berg Balance Scale, BBS), and gait (Functional Ambulation Category, FAC) using VLSM.ResultsVLSM revealed that lower LEFM scores were associated with damage to the bilateral basal ganglia, insula, internal capsule, and subgyral white matter adjacent to the corona radiata. The lesions were more widely distributed in the left than in the right hemisphere, representing motor and praxis function necessary for performing tasks. However, no associations between lesion maps and balance and gait function were established.ConclusionMotor impairment of the lower extremities was associated with lesions in the basal ganglia, insula, internal capsule, and white matter adjacent to the corona radiata. However, VLSM revealed no specific lesion locations with regard to balance and gait function. This might be because balance and gait are complex skills that require spatial and temporal integration of sensory input and execution of movement patterns. For more accurate prediction, factors other than lesion location need to be investigated.

Nerve Conduction Studies of Median Motor Nerve and Median Sensory Branches According to the Severity of Carpal Tunnel Syndrome

Objective To evaluate each digital branch of the median sensory nerve and motor nerves to abductor pollicis brevis (APB) and 2nd lumbrical (2L) according to the severity of carpal tunnel syndrome (CTS). Methods A prospective study was performed in 67 hands of 41 patients with CTS consisting of mild, 23; moderate, 27; and severe cases, 17. Compound muscle action potentials (CMAPs) were obtained from APB and 2L, and median sensory nerve action potentials (SNAPs) were recorded from the thumb to the 4th digit. Parameters analyzed were latency of the median CMAP, latency difference of 2L and first palmar interosseous (PI), as well as latency and baseline to peak amplitude of the median SNAPs. Results The onset and peak latencies of the median SNAPs revealed significant differences only in the 2nd digit, according to the severity of CTS, and abnormal rates of the latencies were significantly lower in the 2nd digit to a mild degree. The amplitude of SNAP and sensory nerve conduction velocities were more preserved in the 2nd digit in mild CTS and more affected in the 4th digit in severe CTS. CMAPs were not evoked with APB recording in 4 patients with severe CTS, but obtained in all patients with 2L recording. 2L-PI showed statistical significance according to the severity of CTS. Conclusion The branch to the 4th digit was mostly involved and the branch to the 2nd digit and 2L were less affected in the progress of CTS. The second digit recorded SNAPs and 2L recorded CMAPs would be valuable in the evaluation of severe CTS.

Compound Nerve Action Potential of Common Peroneal Nerve and Sural Nerve Action Potential in Common Peroneal Neuropathy

To enhance the accuracy for determining the precise localization, the findings of the compound nerve action potentials (CNAPs) of the common peroneal nerve (CPN) were investigated in patients with common peroneal mononeuropathy (CPM) in the knee, and the sural sensory nerve action potentials (SNAPs) were also analyzed. Twenty-five patients with CPM in the knee were retrospectively reviewed. The findings of the CNAPs of the CPN recorded at the fibular neck and the sural SNAPs were analyzed. The lesion was localized at the fibular head (abnormal CNAPs) and at or distal to the fibular head (normal CNAPs). Seven patients were diagnosed as having a lesion at or distal to the fibular neck, and 18 cases were diagnosed as having a fibular head lesion. The sural SNAPs were normal in all the cases of lesion at or distal to the fibular neck. Among 18 cases of fibular head lesion, the sural SNAPs were normal in 7 patients: two cases of conduction block and 5 cases of mild axon loss. Eleven patients showed abnormal sural SNAPs. Of those, 9 cases were severe axon loss lesions and 2 patients were diagnosed as having severe axon loss with conduction block. The recording of the CNAPs may enhance precise localization of CPM in the knee. Moreover, the sural SNAPs could be affected by severe axonal lesion at the fibular head.

Sonography of Carpal Tunnel Syndrome According to Pathophysiologic Type: Conduction Block Versus Axonal Degeneration: Sonography of Carpal Tunnel Syndrome According to Pathophysiologic Type

The purpose of this study was to investigate sonographic findings according to the pathophysiologic type in patients with carpal tunnel syndrome.