A 46-year-old man presents with numbness in his distal fingertips. The patient rarely seeks medical attention and has an insignificant past medical and family history. The patient reports drinking 6 to 7 beers per week and smoking a half pack of cigarettes per day. During neurologic examination, the patient is asked to extend his arms with his eyes shut and maintain his palms facing up. During this maneuver, the patient’s arms both pronate.
Based on the above finding, which of the following is impaired in this patient?
Upper motor neuron pathway. This patient is exhibiting pronator drift on neurologic examination. This is both a specific and sensitive test for upper motor neuron (UMN) disease. UMN disease will very often cause a weakness in supination that allows the pronating muscles to become more dominant. Therefore, when patients are asked to close their eyes and stretch out their arms with their palms facing upward, the affected arm(s) will pronate.
(A) Proprioception can be assessed in various physical examination maneuvers. One of the more common ways to evaluate proprioception is with the Romberg test in which the patient stands with his or her feet together and the practitioner observes if the patient is able to maintain balance with their eyes closed. Patients with impaired proprioception will lose their balance. (C) Although this patient presents with “numbness,” which might lead the reader to the false conclusion that he has peripheral neuropathy leading to impaired tactile sensation (measured by pinprick discrimination), this maneuver was not explicated in the question. (D) Cerebellar function is responsible for balance and coordination and can be assessed by testing for rapidly alternating movements.
A 26-year-old man presents with a stabbing, severe pain in the left side of his face for the past 2 weeks. The pain is described as a “stabbing knife” sensation and occurs about every 12 to 15 minutes. It lasts for about 4 to 5 seconds. The pain is so unbearable that the patient cannot sleep or function in his employment as an accountant. The patient has tried aspirin and acetaminophen to no avail. Physical examination is unremarkable, but the patient has one of the attacks during the visit and visibly shows excruciating pain.
Which of the following is the treatment of choice for this patient’s condition?
Carbamazepine. This patient is presenting with signs and symptoms consistent with a diagnosis of trigeminal neuralgia, a neuropathic disorder characterized by episodes of intensely severe pain in the face that originates from the trigeminal nerve. The drug of choice for trigeminal neuralgia is carbamazepine, an anticonvulsant that stabilizes the inactivated state of voltage-gated sodium channels. The drug is effective in the majority of patients with trigeminal neuralgia; however, one of the rare side effects is aplastic anemia so routine complete blood count (CBC) is necessary with these patients. If carbamazepine fails to alleviate the pain, surgery through decompression or partial resection of the trigeminal nerve is the next best option. (A) Sumatriptan is used in acute migraine attacks and cluster headaches. (B) Acyclovir is used in the treatment of herpes zoster and herpetic neuralgia. However, this presents with pain and a vesicular rash in a dermatomal distribution. (C) Morphine is a narcotic agent used to control pain in several disorders. It has not been shown to be of benefit in patients suffering from trigeminal neuralgia.
A 36-year-old woman presents with a 2-day history of fever, stiff neck, and headaches. She also was reported to have had one seizure just prior to her admission. The patient has a temperature of 39°C, blood pressure of 120/80 mmHg, and heart rate of 106 beats per minute. A lumbar puncture is performed and her CSF studies reveal the following:
Which of the following is the most likely diagnosis in this patient?
Herpes simplex encephalitis. This question is testing one’s ability to distinguish causes of abnormal CSF values. The patient in this question likely has herpes simplex (HSV) encephalitis, which accounts for almost 20% of viral encephalitis cases and presents with fever, focal seizures, and sometimes aphasia, ataxia, hemiparesis, and behavioral symptoms. HSV encephalitis typically affects the temporal lobes of the brain and has an acute onset. CSF analysis is critical in securing the diagnosis. CSF studies reveal lymphocytosis, elevated protein levels, normal glucose levels, and occasionally increased levels of RBCs due to hemorrhagic destruction of the temporal lobes. To solidify the diagnosis, the most specific test is PCR analysis of HSV DNA in the spinal fluid.
(A, D) Bacterial meningitis will present with low glucose in the CSF. In addition, rather than lymphocytosis, increased neutrophils will be seen on CSF analysis. (C) Fungal meningitis often presents with low glucose like bacterial meningitis, but will accompany a lymphocytosis. The patient in this question has a CSF analysis that is consistent with a viral etiology.
A 56-year-old man presents for evaluation of a tremor. The patient reports that over the last 6 months he has been having tremors in both hands that appear to improve with alcohol intake. The patient denies any tremors at rest. The tremor is worsened when he reaches for his coffee cup in the cupboard each morning. The patient reports that his father appeared to be “shaky” but does not recall his exact diagnosis since he passed when the patient was very young. Physical examination demonstrates a tremor that increases in amplitude at the end of goaldirected activities (reaching for a piece of paper).
Which of the following is the medication of choice for this patient’s condition?
Propranolol. The patient in this question is presenting with signs and symptoms consistent with a diagnosis of essential tremor, which is inherited in an autosomal dominant fashion. The distal upper extremities are typically affected and the legs are usually not involved. The tremor increases in amplitude when the arms are outstretched. The drug of choice for essential tremor is propranolol, with clonazepam being a second-line treatment. (B) Trihexyphenidyl is an anticholinergic used in the treatment of the resting tremor seen in Parkinson disease. (C) Haloperidol is the treatment used in Huntington disease, but this disease is characterized by several symptoms including chorea and dementia that are not seen in this patient. (D) Although primidone can be used in the treatment of essential tremor, it is typically used in combination with propranolol.
A 44-year-old woman presents with a 5-month history of headaches and weight loss. The headache is diffusely painful and is markedly worse when the patient coughs or bends over. The patient has vomited several times over the last few months. Neurologic examination reveals papilledema on fundoscopy. An MRI of the head is ordered and shows below.
Which of the following is the most likely diagnosis?
Glioblastoma multiforme. The patient in this question is presenting with a classic description of the most common primary brain tumor, glioblastoma multiforme (GBM). Headaches that worsen with changes in position and that are associated with nausea, vomiting, and weight loss raise the flag of increased intracranial pressure from a space-occupying lesion. A “butterfly”-appearing ring-enhancing lesion (straddling and extending across the corpus callosum) with central necrosis is the classic MRI finding in GBM. Unfortunately, GBM is not only the most common primary brain tumor, but also the most aggressive with survival time typically less than 6 months. (A) Low-grade astrocytomas are more common in children and usually present with seizures. (B) Meningiomas are benign tumors that arise from the meninges. Many are asymptomatic and do not require treatment. Symptomatic meningiomas can be surgically removed. (D) Although metastatic brain tumors are the most common tumor (not a primary tumor such as GBM) found in the brain, the site of metastases is the gray–white junction of the cerebrum. Furthermore, metastases are typically multifocal and spherical.
Click to expand