Local corticosteroid injection versus placebo for carpal tunnel syndrome.

BACKGROUND: Carpal tunnel syndrome (CTS) is a very common clinical syndrome manifested by signs and symptoms of irritation of the median nerve at the carpal tunnel in the wrist. Direct and indirect costs of CTS are substantial, with estimated costs of two billion US dollars for CTS surgery in the USA in 1995 alone. Local corticosteroid injection has been used as a non-surgical treatment for CTS many years, but its effectiveness is still debated. OBJECTIVES: To evaluate the benefits and harms of corticosteroids injected in or around the carpal tunnel for the treatment of carpal tunnel syndrome compared to no treatment or a placebo injection. SEARCH METHODS: We used standard, extensive Cochrane search Methods. The searches were 7 June 2020 and 26 May 2022. SELECTION CRITERIA: We included randomised controlled trials (RCTs) or quasi-randomised trials of adults with CTS that included at least one comparison group of local injection of corticosteroid (LCI) into the wrist and one group that received a placebo or no treatment. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcome was 1. improvement in symptoms at up to three months of follow-up. Our secondary outcomes were 2. functional improvement, 3. improvement in symptoms at greater than three months of follow-up, 4. improvement in neurophysiological parameters, 5. improvement in imaging parameters, 6. requirement for carpal tunnel surgery, 7. improvement in quality of life and 8. ADVERSE EVENTS: We used GRADE to assess the certainty of evidence for each outcome. MAIN RESULTS: We included 14 trials with 994 participants/hands with CTS. Only nine studies (639 participants/hands) had useable data quantitatively and in general, these studies were at low risk of bias except for one quite high-risk study. The trials were conducted in hospital-based clinics across North America, Europe, Asia and the Middle East. All trials used participant-reported outcome measures for symptoms, function and quality of life. There is probably an improvement in symptoms measured at up to three months of follow-up favouring LCI (standardised mean difference (SMD) -0.77, 95% confidence interval (CI) -0.94 to -0.59; 8 RCTs, 579 participants; moderate-certainty evidence). Up to six months this was still evident favouring LCI (SMD -0.58, 95% CI -0.89 to -0.28; 4 RCTs, 234 participants/hands; moderate-certainty evidence). There is probably an improvement in function measured at up to three months favouring LCI (SMD -0.62, 95% CI -0.87 to -0.38; 7 RCTs, 499 participants; moderate-certainty evidence). We are uncertain if there is a difference in median nerve DML at up to three months of follow-up (mean difference (MD) -0.37 ms, 95% CI -0.75 to 0.02; 6 RCTs, 359 participants/hands; very low-certainty evidence). The requirement for surgery probably reduces slightly in the LCI group at one year (risk ratio 0.84, 95% CI 0.72 to 0.98; 1 RCT, 111 participants, moderate-certainty evidence). Quality of life, measured at up to three months of follow-up using the Short-Form 6 Dimensions questionnaire (scale from 0.29 to 1.0; higher is better) probably improved slightly in the LCI group (MD 0.07, 95% CI 0.02 to 0.12; 1 RCT, 111 participants; moderate-certainty evidence). Adverse events were uncommon (low-certainty evidence). One study reported 2/364 injections resulted in severe pain which resolved over "several weeks" and 1/364 injections caused a "sympathetic reaction" with a cool, pale hand that completely resolved in 20 minutes. One study (111 participants) reported no serious adverse events, but 65% of LCI-injected and 16% of the placebo-injected participants experienced mild-to-moderate pain lasting less than two weeks. About 9% of participants experienced localised swelling lasting less than two weeks. Four studies (229 participants) reported that they experienced no adverse events in their studies. Three studies (220 participants) did not specifically report adverse events. AUTHORS' CONCLUSIONS: Local corticosteroid injection is effective for the treatment of mild and moderate CTS with benefits lasting up to six months and a reduced need for surgery up to 12 months. Where serious adverse events were reported, they were rare.

Peripheral nerve neurolymphomatosis: Clinical features, treatment, and outcomes.

This series characterises nine patients with neurohistopathologically proven peripheral nerve neurolymphomatosis. A search of the hospital neuropathology database from 2002 to 2019 identified biopsy proven cases. Clinical data, investigation modalities, treatments, and outcomes were collated. Median age at neuropathy onset was 47 y, the neuropathy commonly as the initial lymphoma disease manifestation. Most (8/9) presented with painful asymmetrical sensory disturbance, with additional cranial nerve involvement in three. Neurophysiology typically demonstrated multiple axonal mononeuropathies. Cerebrospinal fluid protein was often raised (6/8). Magnetic resonance imaging suggested peripheral nerve infiltration in 6/9 and positron emission tomography CT in 4/9. Bone marrow biopsy was abnormal in 6/8. Treatment involved systemic or intrathecal chemotherapy and radiotherapy. Median survival was 23 mo. Neurolymphomatosis is a rare but important cause of neuropathy, particularly in those lacking systemic evidence of lymphoma as correct aggressive treatment can prolong survival. Nerve biopsy is essential to classify lymphoma type and rule out alternatives.

Reading without the left ventral occipito-temporal cortex.

The left ventral occipito-temporal cortex (LvOT) is thought to be essential for the rapid parallel letter processing that is required for skilled reading. Here we investigate whether rapid written word identification in skilled readers can be supported by neural pathways that do not involve LvOT. Hypotheses were derived from a stroke patient who acquired dyslexia following extensive LvOT damage. The patient followed a reading trajectory typical of that associated with pure alexia, re-gaining the ability to read aloud many words with declining performance as the length of words increased. Using functional MRI and dynamic causal modelling (DCM), we found that, when short (three to five letter) familiar words were read successfully, visual inputs to the patient's occipital cortex were connected to left motor and premotor regions via activity in a central part of the left superior temporal sulcus (STS). The patient analysis therefore implied a left hemisphere "reading-without-LvOT" pathway that involved STS. We then investigated whether the same reading-without-LvOT pathway could be identified in 29 skilled readers and whether there was inter-subject variability in the degree to which skilled reading engaged LvOT. We found that functional connectivity in the reading-without-LvOT pathway was strongest in individuals who had the weakest functional connectivity in the LvOT pathway. This observation validates the findings of our patient's case study. Our findings highlight the contribution of a left hemisphere reading pathway that is activated during the rapid identification of short familiar written words, particularly when LvOT is not involved. Preservation and use of this pathway may explain how patients are still able to read short words accurately when LvOT has been damaged.