Acute water intoxication in an adult man: 'dental hyponatraemia' revisited.

The differential diagnosis of hyponatraemia is notoriously wide. However, only a minority is acute, ie develops in less than 48 hours. We describe an unusual cause of water intoxication due to toothache. A 30-year-old man with no medical history of note presented in an acute confusional state. Laboratory results disclosed profound hyponatraemia. Urinary indices were consistent with overdrinking, but in the absence of a reliable history, other aetiologies had to be excluded. This case highlights the benefit of a structured approach in the assessment of electrolyte disturbances.

Sensitivity and specificity of cerebrospinal fluid CXCL13 for diagnosing Lyme neuroborreliosis - a study on 1410 patients and review of the literature.

INTRODUCTION: The B-cell chemoattractant CXCL13 has been suggested as a cerebrospinal fluid (CSF) biomarker for Lyme neuroborreliosis (LNB). Our aim was to substantiate the value of CXCL13 in a large unselected cohort and determine a practical cut-off value to diagnose LNB. METHODS: We retrospectively studied clinical and CSF data of consecutive patients who underwent CSF CXCL13 testing over a period of three years (February 2015 to January 2018) at our academic teaching hospital. Patients were classified into 12 groups according to their final diagnosis. To diagnose LNB (definite or probable/possible), definitions of the respective guideline of the German Neurological Society were applied. RESULTS: Of 1410 patients, 29 were diagnosed with definite LNB and 9 with probable/possible LNB. Median CXCL13 levels were highly elevated in both LNB groups (554 pg/mL and 649 pg/mL, respectively) and the group with bacterial/fungal CNS infections (410 pg/mL; n = 6), while all other groups had markedly lower median CXCL13 levels (p < .001). For definite LNB, the best CXCL13 test cut-off was 55.5 pg/mL with a sensitivity of 96.6% (95% confidence interval, CI, 80.4%-99.8%) and a specificity of 94.9% (95% CI 93.5%-95.9%). All patients with LNB showed clinical improvement after antibiotic treatment. CONCLUSION: In this large monocentric cohort, CSF CXCL13 was found to be a highly sensitive and useful marker for LNB. In conditions with low index of suspicion for LNB, CXCL13 testing may be unwarranted. A review of the literature on the sensitivity and specificity of CSF CXCL13 in the differential of LNB is provided.

Hereditary neuropathy with liability to pressure palsies presenting with sciatic neuropathy.

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal-dominant disorder associated with recurrent mononeuropathies following compression or trivial trauma. Reports on sciatic neuropathy as the presenting manifestation of HNPP are very scarce. We report on a 21-year-old previously healthy man who was admitted with sensorimotor deficits in his left leg. He had no history of preceding transient episodes of weakness or sensory loss. Clinical and electrophysiological examinations were consistent with sciatic neuropathy. Cerebrospinal fluid investigation and MRI of the nerve roots, plexus, and sciatic nerve did not indicate the underlying aetiology. When extended electrophysiological tests revealed multiple subclinical compression neuropathies in the upper limbs, HNPP was contemplated and eventually confirmed by genetic testing.

Objectification of psychogenic postural instability by trunk sway analysis.

INTRODUCTION: The attribution of balance or gait disorders to psychogenic origin can be exceedingly challenging, as clinical tests involving distraction maneuvers are prone to subjective bias. We tested the value of biomechanical balance analysis to identify psychogenic balance and gait (PBG) disorders. METHODS: We quantified and compared the effects of distraction maneuvers on balance based on four stance conditions (eyes open, EO; eyes closed, EC; EO on foam, EOF; and EC on foam; ECF) in subjects with suspected PBG (n = 12), subjects with balance and gait disorder due to multiple sclerosis (MS; n = 12) and healthy controls (n = 12). We measured trunk inclination in transverse plane (°)(2) and the corresponding body angular velocity (°/s). Distractibility of postural stability was analysed using ANOVA with repeated measures. RESULTS: In evident contrast to the MS group and healthy controls, the PBG group showed increased values of (°)(2) and (°/s) and significant distractibility in all four stance conditions. CONCLUSIONS: Biomechanical balance analysis can help clinicians to get objective, quantified results of distraction maneuvers and confirm a positive diagnosis of PBG disorders. Large prospective studies are needed to confirm these results.