Extrapyramidal signs, such as hypokinesia, rigidity, dystonia, and cerebellar manifestations (eg, nystagmus, ataxia), occur in approximately two thirds of patients and are the presenting symptoms in 20%-40%.[12] Corticospinal long tract involvement develops in 40%-80% of patients, including such findings as hyperreflexia, extensor plantar responses (Babinski sign), and spasticity. Iatrogenic CJD, which is related to human gonadotropin, human growth hormone treatment, and dura mater grafts, has a predisposition to manifest as an isolated cerebellar syndrome early during the disease course.[13,14,15,16]
All treatable causes of dementia should be ruled out during investigations; these include herpes encephalitis, Hashimoto encephalitis, and steroid-responsive encephalopathy with autoimmune thyroiditis. In addition, diffuse Lewy body disease, chronic meningitis, paraneoplastic syndromes, lithium poisoning, dementia of motor neuron disease, and HIV encephalopathy are included in the differential diagnosis. The workup includes laboratory tests for dementia to rule out other causes, such as toxic or metabolic encephalopathies.
In CJD, periodic and pseudoperiodic spikes and waves discharges are observed on EEG with slow background.[17,18] Observations of altered signal in the cerebral cortex and basal ganglia during DW-MRI, and detection of protein 14-3-3 in the CSF, help to confirm the diagnosis of CJD.[19,20,21,22] CSF findings are typically normal, with normal opening pressure in CJD; however, CSF protein may be slightly elevated (not more than 100 mg/dL).
Brain biopsy or autopsy is required for a definitive diagnosis of CJD. Brain biopsy, although conclusive in such cases, is usually not performed, owing to an elevated risk for disease transmission.
DW-MRI and fluid-attenuated inversion recovery (FLAIR) reveal hyperintense signal in the cortical ribbons, basal ganglia, and thalamus. Two characteristic signs have been described on MRI: the "hockey stick" sign, which shows hyperintense signal in the putamen and head of caudate nucleus, and the pulvinar sign, which shows hyperintensity in bilateral pulvinar nuclei of thalamus.
MRI has played an increasingly important role in the diagnosis of CJD. Studies on analysis of MRI sequences in CJD have concluded that proton density (PD)-weighted images and DW imaging are superior in identifying signal intensity changes in the basal ganglia compared with T2-weighted or FLAIR images.[23,24,25,26,27,28,29] DW-MRI is also clearly superior in detecting cortical changes. The studies concluded that DW imaging is the most sensitive MRI technique in the diagnosis of CJD.
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Cite this: Sumaira Nabi, Sadaf Fayyaz, Shahzad Ahmed. A 49-Year-Old Man With Forgetfulness and Gait Impairment - Medscape - Jun 27, 2017.
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