Electrophysiological findings in immune checkpoint inhibitor-related peripheral neuropathy.

OBJECTIVE: To report the electrodiagnostic features of immune checkpoint inhibitor (ICI)-related neuropathy. METHODS: We retrospectively reviewed clinical presentations and electrodiagnostic features of 23 patients studied after receiving immune checkpoint inhibitors (ICIs). The presentations for electrodiagnostic evaluation included an acute neuropathy or neuromuscular junction disorder. We applied established electrodiagnostic criteria for polyneuropathy and acute demyelinating neuropathy. RESULTS: We identified acute demyelinating neuropathy (13 cases), axonal sensory motor neuropathy (5), pure sensory neuropathy (4) and mononeuropathy (1). 13 patients had acute demyelinating neuropathy confirmed by demonstrating demyelination in 2 or more nerves; 3 additional patients had demyelination in only one nerve. Analysis of motor nerve conduction parameters revealed demyelination involving median and ulnar nerve distal motor latencies as well as median, ulnar and peroneal nerve conduction velocities. Conduction block was found in median, ulnar and peroneal nerves. The remaining one-third patients without demyelination had acute painful axonal neuropathy. Coexisting myopathic changes (6) and neuromuscular junction dysfunction (4) were also identified. CONCLUSIONS: Our findings suggest that, while immune-mediated motor nerve demyelination is the primary underlying mechanism of ICI-related neuropathy, axonal painful neuropathy can also be an important presentation. Early recognition and effective intervention may reduce morbidity and permanent disability. SIGNIFICANCE: Electrophysiological studies might be useful in the evaluation of ICI-related neuropathy.

Small fiber abnormalities in skin biopsies of patients with benign fasciculations.

OBJECTIVE: To determine whether patients with benign fasciculations have evidence for axonal loss in skin biopsies. METHODS: Epidermal sensory and sweat gland nerve fiber densities were quantified in skin biopsies of 11 patients with benign fasciculations and no other known cause for neuropathy. RESULTS: Nine of the 11 patients (82%) had significantly reduced epidermal or sweat gland nerve fiber densities at the calf or thigh, in comparison with control values. CONCLUSIONS: The presence of reduced epidermal and sweat gland nerve fiber density indicates the presence of axonal loss in patients with benign fasciculations.

Optimization of coronary whole-heart MRA free-breathing technique at 3 Tesla.

Four different techniques for 3-T whole-heart coronary magnetic resonance angiography (MRA) using free-breathing three-dimensional segmented parallel imaging and adiabatic T2-preparation were assessed. Coronary MRA at 3 T is improved by shortening the acquisition window more than employing the highest spatial resolution. Double-oblique whole-heart acquisitions result in better overall image quality and allow for better delineation of the left anterior descending coronary artery. It is possible to attain shorter acquisition windows and a smaller voxel size at 3 T than previously reported at 1.5 T.

Intracranial dural arteriovenous fistula presenting as an enhancing lesion of the medulla.

A case of atypical clinical and imaging manifestations of an intracranial dural arteriovenous fistula (DAVF) is reported. A 53-year-old man presented with orthostatic syncope and tingling of the fingertips of both hands, and the initial imaging findings were interpreted as brainstem mass. A catheter angiogram confirmed the presence of an intracranial DAVF with venous drainage around the brainstem and spinal cord. The lesion was treated by endovascular embolization and the patient remains asymptomatic 9 months after treatment.

Virtual contrast for coronary vessels based on level set generated subvoxel accurate centerlines.

We present a tool for tracking coronary vessels in MRI scans of the human heart to aid in the screening of heart diseases. The vessels are identified through a single click inside each vessel present in a standard orthogonal view. The vessel identification results from a series of computational steps including eigenvalue analysis of the Hessian of the MRI image followed by a level set-based extraction of the vessel centerline. All identified vessels are highlighted using a virtual contrast agent and displayed simultaneously in a spherical curved reformation view. In cases of over segmentation, the vessel traces can be shortened by a click on each vessel end point. Intermediate analysis results of the vessel computation steps can be displayed as well. We successfully validated the tool on 40 MRI scans demonstrating accuracy and significant time savings over manual vessel tracing.