A 64-year-old man comes to the office because he has had 2 falls within the last month. He states that he loses his balance when he tries to turn or stop suddenly while walking. Recently, it has been taking him quite a while to get himself out of bed. He also has hand tremors that started last year in his left hand, but that now have been affecting both hands. Which of the following is the best tool to confirm his diagnosis?

Question

A 64-year-old man comes to the office because he has had 2 falls within the last month.  He states that he loses his balance when he tries to turn or stop suddenly while walking.  Recently, it has been taking him quite a while to get himself out of bed.  He also has hand tremors that started last year in his left hand, but that now have been affecting both hands.  Which of the following is the best tool to confirm his diagnosis?

Quizplus · Accepted Answer

Explanation: This patient is most likely suffering from Parkinson disease (PD), a neurodegenerative disorder associated with accumulation of alpha-synuclein within the neurons of the substantia nigra pars compacta. The 3 cardinal signs of PD are rest tremor, rigidity and bradykinesia. The presence of 2 of these 3 suggests a clinical diagnosis of PD, corroborated by physical examination. To date, there are no imaging or laboratory tests that can be used to confirm this diagnosis with any greater accuracy than physical examination. The most common presenting sign of PD is an asymmetric rest tremor in the distal part of an upper extremity. To summarize, physical examination findings that contribute to a clinical diagnosis of PD include: Tremor: A resting 4 to 6 Hz tremor with a "pill rolling" quality Frequently first manifests in one hand, and may then slowly generalize to involve the other side of the body and the lower extremities Rigidity: Baseline increased resistance to passive movement about a joint which may be uniform (lead pipe) or oscillating (cogwheel) Bradykinesia: Difficulty initiating movements, as when starting to walk or rising from a chair Narrow-based, shuffling gait with short strides and without arm swing (festinating gait) Micrographia (small handwriting) Hypomimia (decreased facial expression) Hypophonia (soft speech) Postural instability: Flexed axial posture Loss of balance during turning or stopping Loss of balance when pushed slightly from a stationary bipedal stance Frequent falls (Choice B) Lumbar puncture is usually normal in PD. Lumbar punctures are important in diagnosing conditions like infectious meningitis, multiple sclerosis, etc. (Choice C) Brain CT scan findings may be unremarkable or non-specific in patients with PD. No imaging study is required in patients with a typical PD presentation. MRI may be useful to exclude items on the differential diagnosis, (eg, multi-infarct state, normal pressure hydrocephalus). Striatal dopamine transporter imaging (DaTscan) helps distinguish parkinsonian syndromes from essential tremor (but not from one another) and its accuracy seems to be equal to that of a careful clinical diagnosis. (Choice D) Electroencephalography (EEG) findings may be unremarkable or non-specific in PD. EEG is typically used in the assessment of patients with seizure disorders, sleep disorders and metabolic disorders affecting the CNS. (Choice E) Peripheral nerve conduction studies may yield unremarkable or non-specific results. Such studies are typically used to assess for peripheral neuropathy. Educational objective: The 3 cardinal signs of Parkinson disease are rest tremor, rigidity, and bradykinesia. The presence of at least 2 of these 3 on physical examination is grounds for a clinical diagnosis of this disease.

A 64-Year-Old Man Comes to the Office Because He Has