Driving under the influence of cocaine and MDMA: Relationship between blood concentrations and results from clinical test of impairment

The general use of cocaine is increasing in recent years, while the trend for 3,4-methylenedioxymethamphetamine (MDMA) is less clear. The relationship between blood concentrations and impairment is poorly understood, which complicates interpretation. The aims of this study were to report prevalence and blood concentrations of cocaine and MDMA in drugged drivers, and to investigate the relationship between blood concentrations and impairment. Samples of whole blood were collected from apprehended drivers in the period 2000-2022, and a clinical test of impairment (CTI) was simultaneously performed. The samples were initially analyzed for cocaine and MDMA using gas chromatography mass spectrometry (until 2009 and 2012, respectively), and later using ultra-high-performance liquid chromatography-tandem mass spectrometry. Overall, cocaine was detected in 2,331 cases and MDMA in 2,569 cases. There were 377 and 85 mono cases of cocaine and MDMA, respectively. In the mono cases, the median cocaine concentration was 0.09 mg/L (range: 0.02-1.15 mg/L), and 54% of the drivers were clinically impaired. The median MDMA concentration was 0.19 mg/L (range: 0.04-1.36 mg/L), and 38% were clinically impaired. There was a statistically significant difference in the median cocaine concentration between drivers assessed as not impaired (0.07 mg/L) and drivers assessed as impaired (0.10 mg/L) (P = 0.009). There was also a significant effect of the blood concentration of cocaine (adjusted odds ratio [aOR] = 6.42, 95% confidence interval [CI] = 1.13-36.53, P = 0.036) and driving during the evening/night-time (aOR = 2.17, 95% CI = 1.34-3.51, P = 0.002) on the probability of being assessed as impaired on the CTI. No significant differences were found for MDMA. Many drivers are not assessed as impaired on a CTI following cocaine or especially MDMA use. For cocaine, a relationship between blood concentrations and impairment was demonstrated, but this could not be shown for MDMA.

Blood Concentrations of Designer Benzodiazepines: Relation to Impairment and Findings in Forensic Cases

The use of designer benzodiazepines appears to be increasing in many countries, but data concerning blood concentrations are scarce, making interpretation of concentrations difficult. The aim of this study was to report blood concentrations of clonazolam, diclazepam, etizolam, flualprazolam, flubromazepam, flubromazolam and phenazepam and to investigate the relationship between blood concentrations and impairment. The concentration data are from blood samples collected from living cases (apprehended drivers and other drug offences) and medico-legal autopsies. The blood samples were analysed for the seven designer benzodiazepines mentioned above by ultra high performance liquid chromatography–tandem mass spectrometry. Positive cases from between 1 June 2016 and 30 September 2019 were included. Blood concentrations and the conclusion from a clinical test of impairment (when available) are reported. The presented seven benzodiazepines were detected in a total of 575 cases, where 554 of these cases concerned apprehended drivers or other criminal offenders. The number of findings and the median (range) concentrations were as follows: clonazolam, n = 22, 0.0041 mg/L (0.0017–0.053 mg/L); diclazepam, n = 334, 0.0096 mg/L (0.0016–0.25 mg/L); etizolam, n = 40, 0.054 mg/L (0.015–0.30 mg/L); flualprazolam, n = 10, 0.0080 mg/L (0.0033–0.056 mg/L); flubromazepam, n = 5, 0.037 mg/L (0.0070–0.70 mg/L); flubromazolam, n = 20, 0.0056 mg/L (0.0004–0.036 mg/L); and phenazepam, n = 138, 0.022 mg/L (0.0018–0.85 mg/L). A designer benzodiazepine was the only drug detected with relevance for impairment in 25 of the 554 living cases. The physician concluded with impairment in 19 of the 25 cases. Most of the concentrations in these cases were relatively similar to or higher than the median reported concentrations. The most frequent other drugs detected were amphetamine, tetrahydrocannabinol, clonazepam and methamphetamine. The presented blood concentrations can be helpful with the interpretation of cases involving one or more of these seven benzodiazepines. The results indicate that concentrations commonly observed in forensic cases are associated with impairment.

Structural stability and thermoelectric performance of high quality synthetic and natural pyrites (FeS2)

Single crystalline pyrite of high quality reveals good thermal- and bad electrical conductivities resulting in poor thermoelectric performance.

The Appearance, Taste, and Concentrations of Zolpidem Dissolved in Still Water and Carbonated Beverages

Zolpidem is a sedative that could be used to drug victims, but its suitability to dissolve in drinks is unknown. In this small study, we added either crushed or whole tablets of zolpidem hemitartrate to carbonated beverages or still water to observe how this affected the taste and appearance. Also, concentrations were measured by ultra-high performance liquid chromatography tandem mass spectrometry at different time intervals. Two crushed tablets (20 mg) in cider (250 mL) lead to a maximum concentration of 84 mg/L zolpidem base after 30 min, while the corresponding concentration after adding fifteen tablets (150 mg) was 467 mg/L. There was little change in taste, but froth and turbidity were observed when adding high doses to carbonated beverages. Carbonated beverages spiked with 20 mg of crushed zolpidem hemitartrate tablets reached concentrations that could cause impairment. Spiking with 150 mg could possibly be lethal if several mouthfuls were ingested.

High frequency of partial SPAST deletions in autosomal dominant hereditary spastic paraplegia

BACKGROUND

Hereditary spastic paraplegia (HSP) is a genetically heterogeneous neurodegenerative disease. The most frequent cause of autosomal dominant HSP is mutation of SPAST (SPG4 locus), but additional pedigrees remain mutation negative by conventional screening despite linkage to SPG4.

OBJECTIVE

To determine the frequency of genomic copy number aberrations of SPAST in autosomal dominant HSP.

METHODS

We developed and validated a multiplex ligation-dependent probe amplification assay targeting SPAST and SPG3A, another gene frequently involved in autosomal dominant HSP. In a multicenter study we subsequently investigated 65 index patients with autosomal dominant HSP, all of whom had previously been screened negative for SPAST mutations. Independent secondary samples, additional family members, and cDNA were analyzed to confirm positive findings.

RESULTS

Aberrant MLPA profiles were identified in 12 cases (18%). They exclusively affect SPAST, represent deletions, segregate with the disease, and are largely pedigree specific. Internal SPAST deletions entail expression of correspondingly shortened transcripts, which vary in stability. Age at onset in SPAST deletion carriers does not differ from that associated with other SPAST mutations.

CONCLUSIONS

Partial SPAST deletions, but not SPAST amplifications and SPG3A copy number aberrations, represent an underestimated cause of autosomal dominant hereditary spastic paraplegia. Partial SPAST deletions are likely to act via haploinsufficiency.

Unexpected pathogenic mechanism of a novel mutation in the coding sequence of SPG4 (spastin)

The authors report a nucleotide substitution (c.1216A>G) in SPG4 (spastin) causing hereditary spastic paraplegia. This apparent missense mutation in the ATPase domain confers aberrant, in-frame splicing and results in destabilization of mutated transcript. Mutated protein is deficient in microtubule-severing activity but, unlike neighboring mutations, shows regular subcellular localization. The authors' data point to haploinsufficiency rather than a dominant negative effect as the disease-causing mechanism for this mutation.

Doppelbilder und kardiogener Schock

Idiopathic giant cell myocarditis is a rare and frequently fatal inflammatory heart disease which leads to congestive heart failure or ventricular arrhythmias. It is often associated with other autoimmune disorders. We report a 39-year-old woman who first presented with diplopia and painful eye movements, the typical clinical picture of orbital myositis. Shortly afterwards, she developed rapidly progressive congestive heart failure due to giant cell myocarditis, which took a fatal course within some weeks. Autopsy confirmed both disorders. This case report underlines the importance of early and repeated monitoring of cardiac function, if orbital myositis is suspected, in order to consider cardiac transplantation, the only efficacious treatment of giant cell myocarditis, in time.

Physiology of modulation of motor cortex excitability by low-frequency suprathreshold repetitive transcranial magnetic stimulation

Many studies show consistently that repetitive transcranial magnetic stimulation (rTMS) with a frequency of 1 Hz and an intensity above the resting motor threshold (RMT) performed for several minutes over the primary motor cortex (M1) leads to a depression of cortical excitability. Furthermore, most studies concur on a facilitation of the non-stimulated contralateral M1. Little is known, however, about the physiological mechanisms underlying these effects. In 11 healthy volunteers, we stimulated the left M1 for 15 min with 1 Hz-rTMS of 115% RMT. Before, immediately after, and 30 min after the rTMS train, we examined short-interval intracortical inhibition (SICI; interstimulus interval (ISI) of 2 and 4 ms), intracortical facilitation (ICF; ISI 10 ms), and short-interval intracortical facilitation (SICF; ISI 1.5 ms) with established paired-pulse protocols. Mean unconditioned motor evoked potential (MEP) amplitudes and RMT were also measured. Two sessions were run at least 1 week apart, in one excitability of the stimulated M1 was tested, in the other one excitability of the non-stimulated M1. rTMS led to the expected reduction of MEP amplitude of the stimulated M1, which was significant only immediately after the rTMS train. rTMS increased MEP amplitude of the non-stimulated M1, which lasted for at least 30 min. RMT, SICI, ICF and SICF did not show any significant change in either M1, except for a long lasting increase of SICF in the non-stimulated M1. In conclusion, the MEP increase in the non-stimulated M1 lasted longer than the MEP decrease in the stimulated M1. Only the long-lasting MEP increase was associated with a specific change in intracortical excitability (increase in SICF). Modulation of motor cortical inhibition did not play a role in explaining the rTMS induced changes in MEP amplitude.

[Thrombotic thrombocytopenic purpura. Reduced activity of von Willebrand factor cleaving protease]

Thrombotic thrombocytopenic purpura (TTP) is a rare thrombotic microangiopathy. Besides anemia and thrombocytopenia, neurological impairment is common in TTP. A 42-year-old woman was admitted to a department of obstetrics/gynecology because of severe vaginal bleeding due to thrombocytopenia. After platelet transfusion, the patient developed a reduced level of consciousness, confusion, headache, and fever. CT scan did not show pathological changes. Transcranial Doppler sonography revealed increased blood flow velocities of all basal cerebral arteries. Because encephalitis was suspected the patient was transferred to the neurological department. CSF and cerebral magnetic resonance imaging studies were normal. Finally, the detection of schistocytes in the peripheral blood smear and the strong elevation of LDH led to the diagnosis of TTP. After plasma exchange over 3 consecutive days the patient achieved complete remission. The diagnosis was confirmed by laboratory tests (activity of ADAMTS13 <5%, IgG antibodies against ADAMTS13). Platelet transfusion may adversely affect the outcome of patients with suspected TTP. Severely deficient activity of the von Willebrand factor cleaving protease (ADAMTS13) is specific for thrombotic thrombocytopenic purpura.

Click evoked myogenic potentials in the differential diagnosis of acute vertigo

OBJECTIVE

In response to loud clicks, a vestibular evoked potential can be recorded from sternocleidomastoid muscles, called "click evoked myogenic potential" (CEMP). This paper reports on the usefulness of CEMP in the differential diagnosis of acute vertigo of presumed vestibular origin.

METHODS

CEMP was examined in 40 patients with acute vertigo of vestibular origin (26 with acute peripheral vestibulopathy, five with Ménière's disease, three with benign paroxysmal positioning vertigo (BPPV), six with psychogenic vertigo) and the results compared with standard caloric reaction (CR). For CEMPs, clicks were delivered unilaterally via a pair of headphones. EMG activity was collected by surface electrodes placed on the sternocleidomastoid belly and averaged.

RESULTS

In 29 patients, CR was unilaterally abnormal, pointing to a peripheral vestibular lesion. Seventeen of them had a corresponding loss of CEMPs; the other 12 patients had a normal CEMP. The remaining 11 patients had normal results in both tests. In comparison with CR, CEMP showed a sensitivity of 59% and a specificity of 100% for peripheral vestibular disorders.

CONCLUSION

CR is a test of the horizontal canal whereas CEMP is thought to be a sacculus test. Different results of CR and CEMP may be due to this difference between target organs stimulated and may be of prognostic value.

Evoked isometric muscle contractions in myopathies: analysis of pathophysiological properties by different stimulus patterns

Isometric twitches of the adductor pollicis muscle following ulnar nerve stimulation were investigated in healthy subjects (n = 35) and patients with different types of myopathies (myotonic dystrophy, n = 19; limb girdle muscular dystrophy, n = 10; metabolic myopathy, n = 6). The changes within the rising part (i.e. within the contraction time, CT) of the isometric twitches after single stimuli were similar in myotonic and limb girdle dystrophies: the first part of CT, which lasts until the maximal contraction rate is achieved, was shortened, whereas the following second part of CT, which lasts until the maximal twitch force is achieved, was normal. In metabolic myopathies the first part was normal, whereas the second part was prolonged. The relaxation was prolonged in all types of myopathies, particularly in metabolic myopathies. Using double stimuli with short interstimulus intervals (ISI), the absolute refractory period of the muscle contraction (healthy subjects: 1.35 +/- 0.16 ms) was shortened in patients with myotonic dystrophy (1.02 +/- 0.11 ms). In the other types of myopathies, the absolute refractory period was only shortened provided that the single twitch force was clearly reduced. A similar dependence on a reduced single twitch force was also found with regard to the maximal force development with two stimuli and the corresponding ISI: the force contributed by a second stimulus was pathologically enhanced if the single twitch force was clearly reduced. The ISI related to the maximal force with two stimuli was shifted towards very short values (healthy subjects: 10.5 ms, myotonic dystrophy: 4.6 ms, limb girdle dystrophies: 5.0 ms). Our results can be attributed to altered kinetics of calcium release and uptake by the sarcoplasmic reticulum in myopathies.

Antineuronal antibody-associated paraneoplastic neuropathy in Hodgkin's disease

Paraneoplastic neurological syndromes in patients with Hodgkin's disease are rare findings. Subacute, paraneoplastic cerebellar degeneration or autonomic dysfunctions were described before. In some of these cases, autoantibodies against central or peripheral nervous system structures were found in serum and CSF. We present a 30-year-old white male who developed a progredient, clinical and electrophysiological distal sensomotoric neuropathy. Six months after the beginning of the neurological disturbances, Hodgkin's disease (Stadium III BE) was diagnosed. Other reasons for neuropathy, such as direct impairment of the peripheral nervous system by tumor masses or drug-induced neuropathy, were excluded. Cerebrospinal fluid (CSF) analysis showed a mild pleocytosis, elevated total protein (9.8 g/l) and identical oligoclonal bands in serum and CSF. Blood-CSF barrier damage was detected by Reiber formula. Indirect immunofluorescence and western blot analysis demonstrated an autoantibody against peripheral and central nervous system structures in serum and CSF. Although the autoantibody responded to a 38-40 kDa-protein in western blot and showed nuclear staining of myenteric plexus and Purkinje cell nuclei in the immunofluorescence test, this antibody was shown to be not identical to anti-Hu. An intrathecal synthesis of the antineuronal antibody was detected by antibody specificity index. Tumor therapy, plasmapheresis and treatment with intravenous immunoglobulins did not improve the neuropathy. According to our knowledge this is the first case of antineuronal antibody-associated sensomotoric neuropathy in Hodgkin's disease.

[Generalized myoclonus as the only symptom of neurosyphilis]

Symptomatic myoclonus syndromes can be caused by a broad range of etiological factors. We report the case of a 40-year-old woman who showed spontaneous and continuous myoclonus with predominance distally and in the arms as the only neurological symptom. CSF evaluation revealed acute neurosyphilis. Six months after antibiotic treatment, the movement disorder had disappeared.

Hereditary motor and sensory neuropathy with spastic paraplegia and optic atrophy: report on a family

We describe two siblings affected by a motor and sensory neuropathy starting in childhood. Already in infancy, a spastic gait disturbance had become obvious, leading later to multiple surgical interventions. In adolescence, progressive loss of vision developed. At the time of our examination, both siblings showed severe weakness and atrophy of the distal muscles of legs and arms. Tendon jerks were brisk in proximal muscles; in the lower extremities, muscle tone was increased. Visual acuity was severely decreased. Nerve conduction studies revealed an axonal degeneration. This finding was confirmed by evaluation of a sural biopsy specimen in one patient, showing only few remaining myelinated fibres without signs of demyelination. This combination of hereditary motor and sensory neuropathy with spastic paraplegia and optic atrophy shows features of both hereditary motor and sensory neuropathy V and VI according to the classification of Dyck, indicating that these subtypes may not represent distinct entities.

Optomotor control of course and altitude in Drosophila melanogaster is correlated with distinct activities of at least three pairs of flight steering muscles

Flight control in the fruitfly Drosophila melanogaster is achieved by minute sets of muscles on either side of the thorax. Control responses of wings and muscles were elicited during fixed flight by moving a striped pattern in front of the eyes. For example, pattern motion from the lower right to the upper left signals to the test fly a rotatory course deviation to the right and simultaneously a translatory altitude displacement downwards. The counteracting response to the displacement of the retinal image is an increase in thrust and lift on the right, accomplished mainly by increasing the wingbeat amplitude (WBA) on that side. A comparison of such responses with the simultaneously recorded action potentials in the prominent basalar muscles M.b1 and M.b2 and axillary muscles M.I1 and M.III1 on either side suggests that three of these muscles act on the WBA more or less independently and contribute to the optomotor control of course and altitude. During flight, M.b1 is almost continuously active with a frequency equal to or slightly below 1 spike per wingbeat cycle. The spikes occur within a narrow phase interval of this cycle, normally at the beginning of the transition from upstroke to downstroke. However, the visual stimulus described above causes a substantial phase lead in M.b1 on the right; the spikes occur shortly before the end of the upstroke. Such phase shifts are accompanied by comparatively smooth 'tonic' responses of the WBA. The activities of M.b2 and M.I1 are normally very low. However, the stimulus described above activates M.b2 on the right in a phase interval approximately two-thirds into the upstroke and M.I1 on the left in a phase interval at the beginning of the downstroke. The spikes tend to occur in bursts. These bursts are correlated with WBA-increasing 'hitches' (rapid changes in amplitude) on the right and WBA-decreasing hitches on the left. As fast 'phasic' responses, the burst-induced hitches are likely to account for the course-controlling 'body saccades' observed during free flight. For unknown reasons, M.I1 is activated by pattern motion but cannot conceivably assist the other muscles in altitude control. Unlike its homologues in larger flies (Musca domestica, Calliphora erythrocephala), M.III1 does not participate in optomotor flight control. Its activation seems to support the termination of flight and wing retraction at rest. The essential properties of the three pairs of muscles M.b1, M.b2 and M.I1 resemble those found in larger flies; the muscles are controlled by motion detectors with muscle-specific 'preferred directions' in the hexagonal array of retinal elements. Optomotor control of the three pairs of muscles in Drosophila melanogaster could explain most, but not all, of the WBA responses recorded so far.

Monosomy 1p is correlated with enhanced in vivo glucose metabolism in meningiomas

The 2-[18F]fluoro-2-deoxy-D-glucose (FDG) uptake of 25 human meningiomas was preoperatively evaluated in vivo by positron-emission tomography (PET). After surgery, meningioma biopsies were analyzed cytogenetically. Five meningiomas showed partial monosomy for chromosome 1p additional to other typical chromosome aberrations. This aberrant karyotype was correlated with increased FDG uptake. Three of five meningiomas with monosomy 1p were classified as grade II according to WHO, while only one of 20 tumors without monosomy 1p was classified as grade II. Thus, monosomy 1p and elevated FDG uptake in PET are to be regarded as cytogenetic and metabolic parameters for the aggressiveness of meningiomas.

[Intracranial manifestations of Langerhans-cell histiocytosis. Nuclear magnetic resonance findings]

We report on 3 patients with intracranial manifestations of Langerhans cell histiocytosis (LH). The results are correlated with histological, clinical and radiological reports on some 70 patients described in the literature as suffering from intracranial LH. Two different morphological pictures can be differentiated. First, typical infiltrates can be seen by microscopy; these can be located in every part of the brain, but are seen mainly in the region of the hypothalamus. These infiltrations are shown as space-occupying lesions with Gd-DTPA enhancement. The other manifestation is a demyelinized lesion with a sparse infiltration of Langerhans cells. These lesions, which are located mainly in the region of the nucleus dentatus of the cerebellum and the brain stem, show increased signal intensity in the T2 sequence and no Gd-DTPA enhancement on MRI.

Subtotal aplasia of myelinated nerve fibers in the sural nerve

Thus far, only very few cases with neuronal maldevelopment in the peripheral nervous system have been reported (Table 1). The present sporadic case manifested itself with peripheral sensorimotor polyneuropathy in early infancy. Clinical findings included pareses and hypaesthesia of distal extremities and severely reduced nerve conduction velocities. During adolescence, cerebellar ataxia developed. Sural nerve biopsy taken at the age of 14.5 years showed severe fascicular hypoplasia, aplasia of large myelinated nerve fibers, and subtotal deficiency of small myelinated nerve fibers without numerical reduction of unmyelinated axons. There was no structural evidence of a progression of myelinated fiber breakdown although some collagen pockets and empty Schwann cell processes among preserved unmyelinated axons indicated some loss of unmyelinated fibers. These findings are interpreted as representing maldevelopment of the myelinated fibers in the peripheral nervous system. Appropriate classification of this unique disease among the known developmental disorders of peripheral nerves is discussed.

Renaut bodies contain elastic fiber components

Renaut bodies (RB) are fusiform endoneurial structures preferentially found at sites of nerve entrapment, often occupying more than 30% of the cross-sectional area of a nerve fascicle. Their composition and significance, however, are still incompletely understood. In this study, further evidence for the link between the appearance of RB and nerve entrapment is presented. Reanaut bodies were already found at the age of 1 year in the median nerve at the level of the wrist, i.e. in the carpal tunnel, a possible site of entrapment. Here, their number increased with age. Renaut bodies were absent, however, in fetal nerves at this site. Many of the cells in RB resembled perineurial cells or pericytes. They were stained with antibodies against vimentin and epithelial membrane antigen and were partially covered by a basal lamina reactive with antibodies against collagen IV, laminin, and s-laminin. Focally accumulated filaments and bundles of 30-40 nm collagen fibrils were major extracellular components of RB. The diameter of the filaments (8-12 nm) corresponded to the size of the microfibril, i.e. the oxytalan component of elastic fibers. Renaut bodies were intensely stained with antibodies against these microfibrils and several types of collagen glycoproteins. On the basis of these results, we conclude that RB are composed of cells that show perineurial differentiation. These cells produce an extracellular matrix highly enriched in elastic fiber components.

The influence of wingbeat synchronous feedback on the motor output systems in flies

Action potentials have been recorded from fibrillar and from non-fibrillar flight muscles of tethered flying flies (Calliphora erythrocephala and Musca domestica).

Analyses of the spike-trains from the fibrillar muscles reveal a clear preference of the spikes to appear at a special phase with respect to the wingbeat cycle. This holds true even in cases of ex­perimentally changed motor output patterns. There seems to be some kind of wingbeat-synchronous feedback which influences the output system phasically.

Crosscorrelations between spike-trains from the fibrillar muscles on the one hand and the non-fibrillar muscles on the other give evidence that there are strong interactions between the output producing neurons of both systems with at least one inhibitory pathway.