Limbic encephalitis due to GABAB and AMPA receptor antibodies: a case series.

BACKGROUND: Two novel antibodies (abs) directed to γ-aminobutyric acid B receptor (GABA(B)R) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) in patients with limbic encephalitis (LE) were first described by the Philadelphia/Barcelona groups and confirmed by the Mayo group. We present a novel series for further clinical and paraclinical refinement. METHODS: Serum and cerebrospinal fluid samples from a diagnostic laboratory were selected if found to be positive for GABA(B)R or AMPAR abs within a broad antineuronal ab panel. Data were retrospectively compiled. RESULTS: In 10 patients, we detected abs to GABA(B)R. Median age was 70 years. Five of them were diagnosed with small cell lung cancer (SCLC). Intrathecal GABA(B)R ab synthesis was found in all six patients with sufficient data available (median ab-index: 76.8). On MRI, we found bilateral mediotemporal and in two cases cortical abnormalities. EEG revealed encephalopathy, partly with epileptiform discharges. Five patients received immunotherapy, two patients tumour treatment and three both therapies. Three patients died, in five patients cognitive functions declined, one patient improved slightly and one patient fully recovered. AMPAR abs were detected in three patients with mnestic disturbances. Median age was 60.7 years. The only female patient was diagnosed with ovarian cancer. None of the patients had intrathecal ab synthesis. MRI findings showed bilateral mediotemporal abnormalities. EEG was normal in all patients. Two of the three immunologically treated patients improved, one patient stabilised on a low level. DISCUSSION: GABA(B)R and AMPAR abs are well associated with LE. GABA(B)R abs lead to severe clinical, neuroradiological and EEG abnormalities with poorer outcome.

Non-dipping nocturnal blood pressure and psychosis parameters in Parkinson disease.

BACKGROUND: Non-motor symptoms are increasingly recognized in Parkinson disease (PD) and include physical as well as psychological symptoms. A psychological condition that has been well studied in PD is psychosis. Cardiovascular autonomic dysfunction in PD can include a reversed or loss of blood pressure (BP) circadian rhythm, referred to as nocturnal non-dipping. The aim of this study was to determine the relationship between 24 h ambulatory blood pressure measurements (ABPM), i.e., absence or presence of nocturnal dipping, and psychosis scores in PD. METHODS: Twenty-one patiens with PD underwent 24 h ABPM using an autonomic protocol. A decrease in nocturnal mean arterial blood pressure of less than 10% was defined as non-dipping. Patients were interviewed (including the brief psychiatric rating scale; BPRS) for the assessment of psychosis. RESULTS: Eleven patients were dippers and 10 were non-dippers. BPRS scores were higher in non-dippers, who, on average, met the criteria for psychosis (mean non-dipper BPRS: 34.3 ± 7.3 vs mean dipper BPRS: 27.5 ± 5.3; cutoff for "mildly ill" 31). There was a correlation between BPRS scores and non-dipping, indicating that those patients who had a blunted nocturnal fall in BP were more prone to psychotic symptoms (Pearson's Correlation = 0.554, p = 0.009). CONCLUSION: These results suggest that, among PD patients, a non-dipping circadian rhythm is associated with more severe symptoms of psychosis than is a dipping circadian rhythm. This association warrants further investigation.

Bortezomib-induced severe autonomic neuropathy.

Peripheral neuropathy is a known side effect of bortezomib therapy. Acute autonomic neuropathy may also follow treatment with this cytotoxic agent used for treatment of multiple myeloma. Here, we report clinical characteristics and patterns of autonomic involvement in a 75-year-old patient who presented with recurring syncopes.

[Anxiety in patients with postural tachycardia syndrome (POTS)]. / Ängstlichkeit bei Patienten mit posturalem Tachykardiesyndrom (POTS).

BACKGROUND: The postural tachycardia syndrome (POTS) is a condition of the autonomic nervous system with symptoms of orthostatic intolerance. In POTS patients, orthostatic stress leads to an overshoot of heart rate increase without a fall in blood pressure. The purpose of this study is to distinguish between anxiety disorders and anxiety as a concomitant phenomenon of orthostatic stress. METHODS: 50 patients fulfilling the diagnostic criteria (orthostatic symptoms, heart rate increase of > 30 bpm or up to > 120 bpm by testing with tilt-table) were included. The study design included a thorough medical history as well as standardised questionnaires about anxiety. RESULTS: The average heart rate increase was 36 bpm after ten minutes of standing and 42 bpm after maximal standing time (max. 45 minutes). POTS patients scored significantly higher than a comparison group in a range of anxiety disorders by using anxiety questionnaires like "Beck Angst-Inventar" (BAI) and trait test of "State-Traits-Angstinventar" which include autonomic items. When questionnaires were used that exclude autonomic items (anxiety sensitivity index: ASI; Interaktions-Angst-Fragebogen: IAF) there was no difference. CONCLUSION: POTS patients do not exhibit signals of anxiety disorders more often than control groups, provided that questionnaires without autonomic items are used.

Cardiac denervation occurs independent of orthostatic hypotension and impaired heart rate variability in Parkinson's disease.

Patients with idiopathic Parkinson's disease (PD) have impaired sympathetically mediated neurocirculatory innervation. Here we analyzed the correlation between cardiac (123)I-metaiodobenzylguanidine (MIBG) uptake, orthostatic hypotension and heart rate variability in treated patients with PD. Orthostatic hypotension (OH) as a hallmark of sympathetic neurocirculatory failure was found with a high prevalence in PD. PD is known to affect cardiac innervation, resulting in a suppressed heart rate variability and a postganglionic noradrenergic lesion. We measured continuous arterial blood pressure in rest and 70 degrees head-up tilt for at least 20 min, heart rate variability in the supine position, standing, deep respiration and Valsalva manoeuvre in 58 patients with PD (27 male, 31 female; mean age 71 years, mean PD duration 5.1 years, Hoehn and Yahr 3.1+/-0.8). Sympathovagal balance was estimated by the low-frequency (LF: 0.04-0.15Hz) and high-frequency bands (HF: 0.15-0.4Hz) ratio in the analysis of heart rate variability in each condition. Myocardial adrenergic function was analyzed by imaging MIBG using the single-photon emission computed tomography technique. MIBG uptake expressed as heart-to-mediastinum ratio was reduced in all PD patients (H/M-ratio: 1.14+/-0.16). We found no correlation between myocardial MIBG uptake and sympathovagal balance, blood pressure or other autonomic findings. The LF/HF ratio in tilt-table testing was significantly more reduced in PD with OH than without OH (2.18 vs. 1.49, p=0.022). MIBG uptake did not differ. It is concluded that scintigraphy with MIBG appears to be a highly sensitive and useful tool to demonstrate sympathetic postganglionic cardiac nerve disturbances. Loss of sympathetic innervation of the heart seems to occur early and independent of orthostatic hypotension, baroreflex failure and impaired heart rate variability in PD.

A novel clinical syndrome revealing a deficiency of the muscarinic M3 receptor.

OBJECTIVES: No clinical disorders have been caused by dysfunction of any of the 5 subtypes (M1-M5) of muscarinic receptors. We present a patient with a novel clinical syndrome that we suggest results from a deficiency of the muscarinic M3 receptor. METHODS: We conducted a comprehensive workup of autonomic function. The patient's disorder was compared to the phenotypic features of male M3 knockout mice. M3 protein quantity was assessed by Western blot and radioligand binding in peripheral blood lymphocytes. Tests for autoantibodies and genetic abnormalities were performed. RESULTS: The disease pattern was characterized by disturbances in micturition, pupil constriction, body weight, and sudomotor function, with normal accommodation, gastrointestinal motility, salivation, and lacrimation, similar to features of male M3 knockout mice. M3 protein quantity was reduced. Genetic tests were unrevealing, but unspecific antinuclear antibodies were present. CONCLUSIONS: The presented clinical syndrome suggests a deficiency of the muscarinic M3 receptor. These results and future evaluation of patients with autonomic deficits may provide insights into the site and functional role of the muscarinic M3 receptor in humans.

Autonomic nervous system laboratories: a European survey.

We present a questionnaire-based survey on methods adopted in European autonomic nervous system (ANS) laboratories in the year 2002. Seventy-nine laboratories from 16 countries in Western and Eastern Europe provided information on test methods, equipment, staff, educational programme and research activities. The results confirmed the anticipated heterogeneity of techniques used to investigate ANS disorders. However, cardiovascular (84.8%) and sudomotor (43.0%) tests were the most common. There were no standards regarding equipment, but devices used varied widely, in part commercially available, in part self-developed. Some ANS laboratories performed cardiovascular tests using standard EMG devices with implemented routines to measure heart rate variability. Many investigators used published normative data (75.4%). Most of the responders were involved in scientific work, half were active in education of trainees. A wide variation was found in number and profession of staff members. As more than 60% of questionnaires were returned by neurologists our results may be limited to neurological ANS laboratories. Given the wide variation of methods and equipment used in European ANS laboratories, minimal standards for routine ANS testing are desirable. Standards may help to compare results of diagnostic tests, evaluate equipment and test laboratory methods and commercial devices and set-up educational programmes.

[Reversible exogenous psychosis in thiazide-induced hyponatremia of 97 mmol/l]. / Reversible exogene Psychose bei Thiazid-induzierter Hyponatriämie von 97 mmol/l.

Severe hyponatraemia may be cause unconsciousness, vomiting, seizures or exogenous psychosis and is associated with a high mortality. We report on a 44-year-old woman who presented with somnolence and psychomotor unrest. After rousing stimuli she showed no verbal response and did not follow any instructions. For three days she suffered from nausea and vomiting. Laboratory values included a natrium serum level of 97 mmol/l. CT scan demonstrated no abnormal findings. Because of severe arterial hypertonia she received for 12 days intensive diuretic therapy with 50 mg hydrochlorothiazide and 100 mg triamterene. Retrospectively, we proved that as a result of saluretic therapy, chronic hyponatremia had already existed before admission. Serum sodium was corrected slowly (< 12 mmol/l) with fluid restriction and normal saline solution. This is considered to be the first case report of a complete restitution after hyponatremia less than 100 mmol/l. We suggest that the preexisting chronic hyponatremia and the slow correction of serum sodium level are responsible for the favorable outcome of this case of severe hyponatremia.

[Diagnostic and prognostic value of additional neurologic diagnosis in alcohol withdrawal delirium]. / Diagnostischer und prognostischer Wert neurologischer Zusatzdiagnostik beim Alkoholdelir.

A severe course of alcohol withdrawal has been observed in 28% of patients in a neurological intensive care unit due to complicating central nerve system (CNS) diseases. In any atypical alcoholic delirium, especially with focal neurological signs, partial seizures, or decreased level of consciousness, CNS diseases like meningoencephalitis, intracranial hemorrhage, or central pontine myelinolysis must be diagnosed by computed tomography (CT) scan and cerebral spinal fluid (CSF) tap. The diagnostic and prognostic value of CT scan and CSF analysis was examined in 32 persons with alcohol withdrawal syndrome or delirium tremens. Neurological complications and cerebral convulsions at the beginning of delirium tremens appear to predispose the patient to a protracted clinical course and necessary mechanical ventilation. Blood-CSF barrier permeability is increased in 70% of alcohol withdrawal patients and that also seems to be a marker of a prolonged clinical course. Cerebral atrophy as shown in CT scan does not play a role in predicting clinical course. In our experience, CT examination or lumbar puncture is not necessarily recommended if clinical signs are typical for alcohol delirium.