Neurological Effects of Stimulants and Hallucinogens.

In this article, we will discuss the history, pharmacodynamics, and neurotoxicity of psychostimulants and hallucinogens. The drugs discussed are widely used and have characteristic toxidromes and potential for neurological injuries with which the practicing clinician should be familiar. Psychostimulants are a class of drugs that includes cocaine, methamphetamine/amphetamines, and cathinones, among others, which produce a crescendoing euphoric high. Seizures, ischemic and hemorrhagic strokes, rhabdomyolysis, and a variety of movement disorders are commonly encountered in this class. Hallucinogens encompass a broad class of drugs, in which the user experiences hallucinations, altered sensorium, distorted perception, and cognitive dysfunction. The experience can be unpredictable and dysphoric, creating a profound sense of anxiety and panic in some cases. Recognizing the associated neurotoxicities and understanding the appropriate management is critical in caring for these patient populations. Several of these agents are not detectable by standard clinical laboratory analysis, making identification and diagnosis an even greater challenge.

Powassan Virus Encephalitis: A Tertiary Center Experience.

BACKGROUND: Powassan virus (POWV) is an emerging arthropod-borne flavivirus, transmitted by Ixodes spp. ticks, which has been associated with neuroinvasive disease and poor outcomes. METHODS: A retrospective study was conducted at Mayo Clinic from 2013 to 2022. We included clinical and epidemiologic data of probable and confirmed neuroinvasive POWV cases. RESULTS: Sixteen patients with neuroinvasive POWV were identified; their median age was 63.2 years, and 62.5% were male. Six patients presented with rhombencephalitis, 4 with isolated meningitis, 3 with meningoencephalitis, 2 with meningoencephalomyelitis, and 1 with opsoclonus myoclonus syndrome. A median time of 18 days was observed between symptom onset and diagnosis. Cerebrospinal fluid analysis showed lymphocytic pleocytosis with elevated protein and normal glucose in the majority of patients. Death occurred within 90 days in 3 patients (18.8%), and residual neurologic deficits were seen in 8 survivors (72.7%). CONCLUSIONS: To our knowledge, this is the largest case series of patients with neuroinvasive POWV infection. We highlight the importance of a high clinical suspicion among patients who live in or travel to high-risk areas during the spring to fall months. Our data show high morbidity and mortality rates among patients with neuroinvasive disease.

Locked in from fulminant GBS after lumbar spine surgery.

Guillain-Barré syndrome (GBS) describes a neurological syndrome characterised by acute, areflexic paralysis, often preceded by an immune stimulating event such as infection or surgery. Spinal surgery as an inciting event is very uncommon with few reported cases. When paraparesis develops in close proximity of surgery, surgical complications should be considered, but if an asymptomatic clinical interval precedes a progressive ascending weakness this association weakens and may support an immunological mechanism. GBS after lumbar surgery is wholly unexpected and thus there are significant challenges in recognising and making the diagnosis. We report a case of fulminant GBS that progressed to loss of all motor function following elective lumbar spine surgery.

Association of Complex Repetitive Discharges With Chronicity and Clinical Symptoms in Radiculopathies.

PURPOSE: Complex repetitive discharges (CRDs) are incompletely understood needle electromyography (EMG) waveforms seen in both myopathic and neurogenic disorders including radiculopathies. This study aimed to clarify the significance of CRDs in patients with radiculopathies. METHODS: This case-control study randomly identified 100 patients with needle EMG evidence of radiculopathy demonstrating at least one CRD in the electrodiagnostically involved myotome between January 2017 and January 2022. These patients were compared with 100 randomly selected patients with EMG evidence of radiculopathy without CRDs controlled for sex, age at EMG testing, and affected nerve root segment. Patient clinical symptoms, neurologic examination, EMG features, and imaging were analyzed. A paired sample t-test for categorial data and χ2 test for nonparametric data were used for statistical analysis with significance defined as P < 0.05. RESULTS: Patients with radiculopathies with CRDs had longer disease duration averaging 59 months (range 1-480) compared with patients with radiculopathies without CRDs averaging 26 months (range 1-192, P < 0.01). Clinical symptoms of paresthesias and weakness were both significantly more common in patients with radiculopathies with CRDs than those without CRDs (P < 0.01 and 0.01, respectively). Needle EMG demonstrated a greater average number of muscles with neurogenic motor unit potentials per radiculopathy in patients with radiculopathies with CRDs compared with those without CRDs. Imaging studies of patients with radiculopathies with CRDs were more likely to reveal evidence of nerve root compression (P < 0.01). CONCLUSIONS: The presence of CRDs in patients with radiculopathies is consistent with clinically more symptomatic radiculopathies and a longer duration of nerve root compromise.