Neurological complications of renal dialysis and transplantation.

Neurological complications from renal replacement therapy contribute significantly to morbidity and mortality in patients with renal failure. Such complications can affect either the central or peripheral nervous systems. Most neurological disturbances associated with the uraemic state do not respond fully to renal replacement therapy. There are also complications specifically associated with dialysis and transplantation. A multidisciplinary approach, involving both nephrologists and neurologists, is critical for the diagnosis and effective management of these disorders.

Type 2 diabetes mellitus and microvascular complications 1 year after Roux-en-Y gastric bypass: a case-control study.

AIMS/HYPOTHESIS: We aimed to examine the effects of bariatric surgery on microvascular complications in patients with type 2 diabetes using objective measures. METHODS: Prospective case-control study of 70 obese surgical patients with type 2 diabetes undergoing gastric bypass surgery matched for age, sex and duration of diabetes to 25 medical patients treated using international guidelines. Microvascular complications were assessed before and 12-18 months after intervention using urine albumin creatinine ratio (ACR) measurements, two-field digital retinal images and peripheral nerve conduction studies (in the surgical group only). RESULTS: Urine ACR decreased significantly in the surgical group but increased in the medical group. There were no significant differences between the surgical and medical groups in the changes in retinopathy. There were no changes in the nerve conduction variables in the surgical group. CONCLUSIONS/INTERPRETATION: In the short term, bariatric surgery may be superior to medical care in the treatment of diabetic nephropathy, but not retinopathy or neuropathy.

Entrapment of the lateral cutaneous nerve of the calf.

Isolated lesion of lateral cutaneous nerve of the calf (LCNC), particularly due to entrapment, is rarely reported in the literature. Patients usually present with sensory symptoms in the lateral aspect of the calf. Treatment is usually by local applications or local steroid/anaesthetic injection. We report the first case of LCNC entrapment in a 35-year-old man which is documented by nerve conduction studies. The patient had a temporary improvement following a local anaesthetic/steroid injection. Owing to the recurrence of symptoms, the patient opted for surgery. About 1 year after surgery, the symptoms disappeared completely.

Treatment for meralgia paraesthetica.

BACKGROUND: Meralgia paraesthetica is a clinical syndrome for which a number of treatments are in common use, including conservative measures, injection of corticosteroid with local anaesthetic and surgery. We aimed to examine the evidence for the relative efficacy of these interventions. This review was first published in 2008. Searches were updated in 2010 and 2012. OBJECTIVES: To assess the relative efficacy of commonly used treatments for meralgia paraesthetica. SEARCH METHODS: We searched the Cochrane Neuromuscular Disease Group Specialized Register (1 October 2012), CENTRAL (2012, issue 9 in The Cochrane Library), MEDLINE (January 1966 to October 2012), EMBASE (January 1980 to October 2012) and CINAHL Plus (January 1937 to October 2012) for randomised controlled studies. Non-randomised studies were identified by searching MEDLINE (January 1966 to October 2012) and EMBASE (January 1980 to October 2012). We also inspected the reference lists of these studies. SELECTION CRITERIA: We were unable to identify any randomised controlled trials (RCTs) or quasi-RCTs. We therefore looked for high quality observational studies meeting the following criteria: (1) At least five cases of meralgia paraesthetica. (2) Follow-up of at least three months after intervention (if any). (3) At least 80% of cases followed up. DATA COLLECTION AND ANALYSIS: Three authors independently extracted relevant data from each study meeting the selection criteria and transferred into a data extraction form. MAIN RESULTS: We found no RCTs or quasi-RCTs in the original review or updates in 20011 and 2012. Cure or improvement have been described in high quality observational studies: (1) A single study describes spontaneous improvement of meralgia paraesthetica in 20 (69%) of 29 cases. (2) Four studies evaluating the injection of corticosteroid and local anaesthetic found cure or improvement in 130 (83%) out of a combined total of 157 cases. (3) Surgical treatments have been found to be beneficial in 264 (88%) out of 300 cases treated with decompression (nine studies); and 45 (94%) out of 48 cases treated with neurectomy (three studies). (4) Ninety-nine (97%) out of 102 patients with iatrogenic meralgia paraesthetica recovered completely (three studies). AUTHORS' CONCLUSIONS: In the absence of any published RCTs or quasi-RCTs, the objective evidence base for treatment choices in meralgia paraesthetica is weak. High quality observational studies report comparable high improvement rates for meralgia paraesthetica following local injection of corticosteroid and surgical interventions (either nerve decompression or neurectomy). However, a similar outcome has been reported without any intervention in a single natural history study.

Pathological yawning as an ictal seizure manifestation in the elderly.

Excessive yawning has been reported in the peri-ictal period preceding or following seizures. We describe an exceptional case of an elderly man with impairment of consciousness and paroxysmal excessive yawning. We hypothesise that this can be regarded as an autonomic seizure originating from diencephalic/brainstem structures, manifesting with yawning as an ictal phenomenon.

Cervical radiculopathy: discrepancy or concordance between electromyography and magnetic resonance imaging?

In the screening of patients with cervical radiculopathy, a relatively common finding is the discrepancy between normal needle electromyography (EMG) and abnormal MRI, or vice versa. We carried out a retrospective study to assess the relationship between needle EMG and MRI findings in the preoperative evaluation of patients with cervical radiculopathy. The records of 147 patients were reviewed; 58 patients (M = 32, F = 26; age 53 ± 9) were included in the study. Needle EMG examination was abnormal in 28 patients. MRI abnormalities were found in all 58 patients, showing degenerative changes not affecting the nerve root in 15 and foraminal stenosis affecting the nerve root in 43; in the latter, needle EMG was abnormal in 28 patients and normal in the remainder. Concordance between EMG and MRI level of abnormality was found in 71% of patients with non-dermatomal symptom distribution. Concordance between clinical level, EMG and MRI abnormality was found in 50% of patients with C5, in 70% with C6 and in 67% with C7 symptom distribution. When EMG and MRI level of abnormality was discordant, the EMG abnormalities corresponded to the clinical level of symptom distribution. The results of our retrospective study reveal that in the majority of cases of cervical radiculopathy, EMG and MRI level of abnormalities are concordant. When there is discordance between EMG and MRI findings, the EMG helps in the guidance of patient selection for surgical intervention because it provides evidence of nerve root lesion and offers a dynamic tool in the follow-up evaluation.

Asymmetry of visual function in migraine with aura: correlation with lateralisation of headache and aura.

BACKGROUND: Asymmetry of visual phenomena and headache is an important feature of migraine with aura. METHODS: This asymmetry was explored by assessment of visual illusions, hemifield spatial contrast detection (HCD) and hemifield pattern reversal visual evoked potentials (HVEPs) in 47 migraineurs with aura (MA), who were not taking prophylactic medications, and 62 controls with the same age range (16-59). RESULTS: Illusions were greater and HCD was poorer in MA than in controls. There were no group differences with respect to P100 amplitude. The longer the duration of migraine the poorer the HCD. When the aura was consistently unilateral it was associated with greater illusions, reduced HCD and reduced hemifield P100 amplitude. These findings were not related to the side of headache. CONCLUSION: The lateralised changes suggest that the visual dysfunction occurs at a cortical level, and the correlation with the side of the aura suggests that dysfunction is most likely to occur in an area of preexisting anomaly of neural function.

The impact of intermittent retraction on paraspinal muscle function during lumbar surgery.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To study the effect of surgical retraction on paraspinal muscle function and investigate the effect of intermittent muscle retraction. SUMMARY OF BACKGROUND DATA: Paraspinal muscle retraction leads to increased intramuscular pressure with a reduction in local blood flow resulting in ischemic damage. This may lead to muscle dysfunction and increased back pain after surgery. METHODS: Two groups of 20 patients underwent one-level decompressive lumbar surgery. Group A underwent continuous muscle retraction, group B underwent intermittent muscle retraction. All patients completed pain questionnaires and underwent spinal strength assessment, paraspinal needle electromyography (EMG) before and after surgery, and had intraoperative muscle biopsy analysis using the technique of birefringence. RESULTS: Pain questionnaires revealed a reduction in back pain in all patients following surgery; patients with shorter retraction times had less pain (P < 0.05). Paraspinal muscle histochemistry revealed patients with shorter muscle retraction times and patients who underwent intermittent muscle retraction has less damage (P < 0.05). Isometric strength testing revealed patients in the intermittent retraction group had a less profound reduction in strength after surgery (P < 0.05). Needle EMG data and pain questionnaires showed no differences between the continuous and intermittent groups, although EMG data did show that muscle shows evidence of reinnervation after surgery. CONCLUSION: Although histologically there was a reduction in muscle damage in patients that underwent intermittent retraction, there was no benefit on clinical outcome. Paraspinal muscle shows evidence of reinnervation after surgery.

Treatment for meralgia paraesthetica.

BACKGROUND: Meralgia paraesthetica is a clinical syndrome for which a number of treatments are in common use, including conservative measures, injection of corticosteroid with local anaesthetic and surgery. We aimed to examine the evidence for the relative efficacy of these interventions. OBJECTIVES: To assess the relative efficacy of commonly used treatments. SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Group Trials Register (April 2008), MEDLINE (January 1 1966 to April 18 2008), EMBASE (January 1 1980 to May 12 2008) and CINAHL (January 1 1980 to May 12 2008) for randomised controlled studies. Non-randomised studies were identified by searching MEDLINE (January 1 1966 to April 18 2008) and EMBASE (January 1 1980 to May 12 2008). We also inspected the reference lists of these studies to identify further studies. SELECTION CRITERIA: We were unable to identify any randomised controlled or quasi-randomised controlled trials. We therefore looked for high quality observational studies meeting the following criteria:(1) At least five cases of meralgia paraesthetica.(2) Follow-up of at least three months after intervention (if any).(3) At least 80% of cases followed up. DATA COLLECTION AND ANALYSIS: Relevant data from each study meeting the selection criteria were extracted independently by all three authors and transferred into a data extraction form created for the review. MAIN RESULTS: We found no randomised controlled or quasi-controlled trials. Cure or improvement have been described in high quality observational studies:(1) A single study describes spontaneous improvement of meralgia paraesthetica in 20 (69%) out of 29 cases.(2) Four studies evaluating the injection of corticosteroid and local anaesthetic found cure or improvement in 130 (83%) out of a combined total of 157 cases.(3) Surgical treatments have been found to be beneficial in 264 (88%) out of 300 cases treated with decompression (nine studies); and 45 (94%) out of 48 cases treated with neurectomy (three studies).(4) Ninety-nine (97%) out of 102 patients with iatrogenic meralgia paraesthetica recovered completely (three studies). AUTHORS' CONCLUSIONS: In the absence of any published randomised controlled or quasi-randomised controlled trials, the objective evidence base for treatment choices in meralgia paraesthetica is weak. High quality observational studies report comparable high improvement rates for meralgia paraesthetica following local injection of corticosteroid and surgical interventions (either nerve decompression or neurectomy). However, a similar outcome has been reported without any intervention in a single natural history study.

The value of neurophysiological and imaging studies in predicting outcome in the surgical treatment of cervical radiculopathy.

It is not always easy to predict the degree of symptomatic improvement to be expected in a patient undergoing surgery for cervical disc herniation and radiculopathy. Here we investigate whether preoperative electromyography (EMG) can help select those most likely to benefit from intervention. We prospectively evaluated 20 patients whose required operative level was unclear after clinical examination and MRI scan alone. The surgical procedures was anterior cervical interbody fusion with the AcroMed carbon fibre cage. Clinical assessment employed using validated scoring systems (Prolo functional and economic scoring system). Patients underwent MRI preoperatively, and were assessed pre and postoperatively with neurophysiological studies (NPS) including nerve conduction studies and concentric needle EMG. Patients with preoperative evidence of cervical nerve root involvement on EMG (group A, n = 8) had better outcome (P = 0.001) following discectomy and anterior fusion than patients who had no evidence of nerve root damage on EMG (group B, n = 12). Prolo mean score +/- SEM for group A was 7.375 +/- 0.3750 and for group B was 5.583 +/- 0.2876. Thus, NPS are a valuable tool in selecting patients in this subgroup for cervical surgery.

Mutations in the human LARGE gene cause MDC1D, a novel form of congenital muscular dystrophy with severe mental retardation and abnormal glycosylation of alpha-dystroglycan.

The congenital muscular dystrophies (CMD) are a heterogeneous group of autosomal recessive disorders. A new pathomechanism has recently been identified in a group of these disorders in which known or putative glycosyltransferases are defective. Common to all these conditions is the hypoglycosylation of alpha-dystroglycan. Fukuyama CMD, muscle-eye-brain disease and Walker-Warburg syndrome, each associated with eye abnormalities and neuronal migration defects, result from mutations in fukutin, POMGnT1 and POMT1, respectively, while mutations in the fukutin-related protein (FKRP) gene cause congenital muscular dystrophy 1C, typically lacking brain involvement. Another putative glycosyltransferase, Large, is mutated in the myodystrophy mouse. The human homologue of this gene is therefore a strong candidate for involvement in novel forms of muscular dystrophy. We studied 36 patients with muscular dystrophy and either mental retardation, structural brain changes or abnormal alpha-dystroglycan immunolabelling, unlinked to any reported CMD loci. Linkage analysis in seven informative families excluded involvement of LARGE but sequencing of this gene in the remaining 29 families identified one patient with a G1525A (Glu509Lys) missense mutation and a 1 bp insertion, 1999insT. This 17-year-old girl presented with congenital muscular dystrophy, profound mental retardation, white matter changes and subtle structural abnormalities on brain MRI. Her skeletal muscle biopsy showed reduced immunolabelling of alpha-dystroglycan. Immunoblotting with an antibody to a glycosylated epitope demonstrated a reduced molecular weight form of alpha-dystroglycan that retained some laminin binding activity. This is the first description of mutations in the human LARGE gene and we propose to name this new disorder MDC1D.