Endocannabinoid signaling depends upon the CB1 and CB2 cannabinoid receptors, their endogenous ligands anandamide and 2-arachidonoylglycerol, and intracellular proteins that mediate responses via the C-terminal and other intracellular receptor domains. The CB1 receptor regulates and is regulated by associated G proteins predominantly of the Gi/o subtypes, β-arrestins 1 and 2, and the cannabinoid receptor-interacting protein 1a (CRIP1a). Evidence for a physiological role for CRIP1a is emerging as data regarding the cellular localization and function of CRIP1a are generated. Here we summarize the neuronal distribution and role of CRIP1a in endocannabinoid signaling, as well as discuss investigations linking CRIP1a to development, vision and hearing sensory systems, hippocampus and seizure regulation, and psychiatric disorders including schizophrenia. We also examine the genetic and epigenetic association of CRIP1a within a variety of cancer subtypes. This review provides evidence upon which to base future investigations on the function of CRIP1a in health and disease.

Wrist drop is a common presentation in neurology. To localize the lesion, clinicians can focus on testing finger extension, elbow flexion with semi-pronated forearm, and elbow extension among other muscle groups as well as identifying dermatomes of numbness. Once the lesion is localized, electrophysiology or imaging can guide to an underlying etiology. Here we describe a case that illustrates the importance of using a stepwise approach to diagnose the etiology of wrist drop in a patient with a cancer history. A 65-year-old woman with diffuse large B-cell lymphoma in remission presented with new onset wrist drop, severe pain, numbness, and tingling concerning for peripheral nerve injury. Imaging findings from PET, venous ultrasound, nerve conduction velocity study (NCV), and MRI were conflicting favoring deep venous thrombosis, cancer recurrence, or peripheral nerve sheath tumor. A biopsy was ultimately required to confirm the diagnosis.

Purpose:Previous ultrasonographic studies of individuals with chronic inflammatory demyelinating polyneuropathy (CIDP) have shown nerve enlargement at several sites. This prospective study compares only the bilateral median and ulnar nerves of individuals with CIDP with reference values to determine the clinical usefulness of this focused approach as a diagnostic tool.Methods:The cross-sectional area, echogenicity, and vascularity of the bilateral median and ulnar nerves of 25 subjects with CIDP were measured using ultrasound. Nineteen had typical CIDP based on the European Federation of Neurological Societies and the Peripheral Nerve Society guidelines, whereas six had atypical CIDP and were diagnosed based on clinical impression.Results:Focal nerve enlargement was found in at least one segment in all subjects. Subjects with typical CIDP had larger cross-sectional areas compared with subjects with atypical CIDP.Conclusion:A focused ultrasound study, involving only the median and ulnar nerves, is sensitive for the detection of nerve enlargement in CIDP. Measuring the cross-sectional area of the median and ulnar nerves is clinically feasible and may help establish the diagnosis of CIDP.