Shahnaz Miri

α-synuclein in the inner retina in parkinson disease

Behavioral, electrophysiological, and imaging data reveal impaired visual processing and altered retinal morphology in Parkinson disease. Are visual changes epiphenomena? We report the presence of misfolded α‐synuclein in the retina, not hitherto shown, in discrete retinal neurons within the inner retina. They demonstrate the histopathology that may underlie impaired vision and retinal remodeling in Parkinson disease. Furthermore, the histological localization of α‐synuclein gives clues to the nonsynaptic mode of α‐synuclein propagation. ANN NEUROL 2014;75:964–966

Venturing into the no-man's land of the retina in Parkinson's disease.

The development of optical coherence tomography (OCT) has led to increasing interest in the retina in Parkinsons disease (PD). The retina is a multilayered tissue: looking into the eye from the outside, these layers comprise the nerve fiber layer (NFL); the ganglion cell layer (GCL); the inner plexiform layer (IPL), which contains the interconnecting plexus, including tyrosine hydroxylase‐positive (dopaminergic) fibers of amacrine cells; the inner nuclear layer; and several outer retinal layers. Commercial spectral‐domain OCT has a specific program for detecting peripapillary NFL defects and a different macular program for diabetic retinopathy. Specific programs for PD are not commercially available. Taking all studies together, it seems that macular programs have a higher diagnostic yield than NFL programs, but the numbers of studies and examined patients are relatively small. It is not certain that all retinal thinning in PD is due to dopaminergic neuronal loss. When applying OCT, the where (region of interest) and the what of the focus of automated programs must be considered. With these caveats, one could take advantage of the power of OCT for looking in‐depth into the terra incognita of individual retinal layers at the fovea and perhaps at other appropriate retinal locations.

Prevalence and associated features of restless legs syndrome in a population of Iranian women during pregnancy

To investigate the prevalence of restless legs syndrome (RLS) during pregnancy and to evaluate factors associated with RLS in a population of Iranian pregnant women.

A combination of retinal morphology and visual electrophysiology testing increases diagnostic yield in Parkinson's disease.

BACKGROUND Impaired vision and remodeled foveal pit have been demonstrated in Parkinsons disease (PD) patients using different techniques. METHODS Ten PD (20 eyes) and eight healthy controls (HC) subjects (16 eyes) were enrolled. Subjects were evaluated for N70 and P100 latencies using two-channel VEP with pattern reversal and on/off pattern; Contrast sensitivity (CS) using Pelli-Robson chart; macular thickness measured using Zeiss-HD optical coherence tomography (OCT). RESULTS PD patients had a significantly delayed N70 (reversal pattern) and P100 (on/off pattern), lower CS score, and decreased retinal thickness at temporal 1.5-2.5 mm from the foveola. N70 latency was negatively correlated with CS (R = -0.419, P = 0.01) and average GCL-IPL thickness (R = -0.529, P = 0.001). CS was positively correlated with parafoveal thickness (R = 0.490, P = 0.002). A combination of parafoveal thickness and CS score yielded an AUC of 0.784 for PD discrimination which increased to 0.844 when combined with N70 and P100 measures. CONCLUSION A combination of pattern reversal VEP latency, CS score, and inner retinal foveal thickness measures has a high diagnostic yield for PD.

The avascular zone and neuronal remodeling of the fovea in Parkinson disease

Inner foveal thinning and intracellular alpha‐synuclein were demonstrated in the retina in Parkinson disease. While pathognomonic alpha‐synuclein is associated with embryonic dopaminergic (DA) neurons, postmortem studies in the nervous system and retina show prominent effect also in non‐DA neurons. We evaluated foveal capillaries and foveal thickness in 23 Parkinson disease subjects and 13 healthy controls using retinal fluorescein angiography and optical coherence tomography. The size of the foveal avascular zone inversely correlates with foveal thinning. Foveal thinning highly correlates with motor impairment and also disease duration. Quantifying capillary and neuronal remodeling could serve as biological markers.

A novel retinal biomarker for Parkinson's disease: Quantifying the foveal pit with optical coherence tomography

Optical coherence tomography offers a potential biomarker tool in Parkinsons disease (PD). A mathematical model quantifying symmetry, breadth, and depth of the fovea was applied.

OCT and Parkinson’s Disease

Research in Parkinson’s disease (PD) using Optical coherence tomography (OCT) is rapidly expanding. These studies aim to better understand the pathobiology of PD and define an accessible biomarker for early diagnosis, monitoring disease severity and progression. Peripapillary retinal nerve fiber layer (pRNFL) and macular scans in many, but not in all studies, demonstrated significant retinal thinning in PD patients and its correlation with disease severity. There is a critical need to define the best region of interest in OCT scans for PD patients. In this chapter, we describe the detailed method of OCT application and evaluation of the retinal thickness in PD. Establishing a unified method of retinal thickness analysis by OCT would be a major advance for further research studies and clinical application of OCT.

Teaching Video NeuroImages: Hand tremor, tongue and perioral fasciculation in a patient with Kennedy disease

A 54-year-old man presented with a 10-year history of progressive gait difficulty, muscle weakness, and fatigue. Clinical examinations revealed mild nasal speech; postural hand tremor; absence of deep tendon reflexes; atrophy and fasciculation in tongue, facial (perioral), and limb muscles; and gynecomastia (video on the Neurology® Web site at Neurology.org). Nerve conduction studies had normal results; however, needle EMG demonstrated a neurogenic pattern with spontaneous activity (fibrillation, positive sharp wave, and fasciculation) in cranial and limb muscles. Genetic testing confirmed (CAG expansion of the androgen receptor gene on X chromosome) the diagnosis of spinobulbar muscular atrophy or Kennedy disease, an X-linked adult-onset degenerative disorder of motor neurons.1,2