September ’12

Medical Student Elective

Case of the Month
September
Submitted by: Christopher Richardson, MS4, Stony Brook University School of Medicine

Chief Complaint
“My leg gave out.”


HPI
65 year-old male brought in by EMS 30 minutes after sudden onset of right leg weakness, causing him to stumble while walking with his sister downtown. He denies actually falling or striking his head or extremities, and was able to sit down in a controlled fashion. His sister notes that he just arrived in NYC from his home in Virginia and thinks the episode was provoked by the bright lights and crowds in Manhattan. She states he has had trouble walking for several years. He was able to stand and bear weight immediately after the incident. An EMT who evaluated the patient on scene notes his initial blood pressure was 240/100 and that he seemed confused when EMS arrived. He denies any pain, headache, weakness, or numbness at this time, and states he feels well, but is worried about why this happened.


PMH
Glaucoma. No history of hypertension, CAD, or stroke.
Social history: None Relevant.


Meds
Timolol ophthalmic solution.


Allergies
None.


PE (pertinent)
Vitals: BP 191/98; HR 112; RR 24; O2 99% on RA.
General: Patient laying in bed; hair unkempt; clothing damp and smelling of urine.
Head and neck: No abrasions/lacerations/contusions; pupils equal and reactive; mouth and pharynx normal; neck supple.
Pulmonary: Lungs clear to auscultation bilaterally with no wheezes or rales.
Cardiac: Tachycardic with regular rhythm and no murmurs or gallops; no jugular venous distension or peripheral edema.
Abdomen: Normal bowel sounds; belly is soft, non-tender and non-distended.
Neuro: Patient is alert and oriented to person, place and time, but is generally slow to answer questions and needs them repeated multiple times. Cranial nerves II-XII are intact. Strength is equal and 5/5 bilaterally in upper and lower extremities. Sensation is grossly intact. Gait was not assessed at this time.

Ddx and Workup
Initially, a broad differential diagnosis was considered, with intracranial hemorrhage, stroke, hypertensive emergency, arterial dissection, myocardial infarction and toxic ingestion primary considerations.

EKG
Sinus tachycardia with no concerning features.

CT Head
Patient sent for an emergent non-contrast CT of the head.




What is the most likely diagnosis for this patient?




Progress
Obviously, the patient has very prominent ventricles as demonstrated by the initial Emergency Department CT scan. The question now becomes, does this represent a pathologic hydrocephalus, and, if so, is it of the communicating or obstructive variety?
The CT shows “marked dilation of the ventricular system without corresponding enlargement of the cerebral sulci.” This suggests a true hydrocephalus, as opposed to prominent ventricles in a patient with atrophy of brain parenchyma from chronic dementia or traumatic brain injury.


Disposition
Neurosurgery was consulted and the patient admitted to the hospital. A brain MRI was obtained the next day.


MRI Brain


The MRI shows “marked enlargement of the ventricles without obstructing mass lesion.”


What is the most likely diagnosis for this patient?
Normal Pressure Hydrocephalus


Course and Treatment
Early in his hospital course, the patient was noted to ambulate with a walker for a maximum distance of 20 feet. His neurologic exam remained unchanged from his presentation in the ED. He was continually noted to have difficulty expressing himself and required extra time to answer questions.
The treatment for normal pressure hydrocephalus is a ventricular shunt, which is effective in approximately 60 percent of cases in reversing some of the gait and cognitive effects of the disorder. In order to identify patients most likely to respond to treatment, a trial of CSF drainage is performed, and the patient’s response observed.
A lumbar drainage procedure was performed on our patient, whereby a small amount (up to 10cc) of CSF was drained every hour. Over the course of several days, the patient’s mental status improved and he was able to increase his daily ambulation.
On the basis of this improvement with lumbar drainage, the patient was recommended for a ventriculoperitoneal shunt, which he received three weeks after first visiting the ED.


CT Scan Post-VP Shunt


Follow-Up
The patient was discharged to inpatient rehab, and one week following the procedure he was noted to be able to walk up to 280 feet using a walker and perform all ADLs unassisted. His sister reports that he responds more clearly to questions and seems more expressive in his language, and that his gait is more fluid than she has seen it in years. The patient plans to return to his home in Virginia. His blood pressures returned to the normal range during his admission without any requirement for medication.


Take Home Messages

  • Prevalence has been estimated at between 3 and 181 per 100,000 adults, with rates increasing with age.
  • Can be seen at all ages when secondary to SAH or chronic meningitis. Idiopathic NPH is much more common in people older than 65.
  • Commonly associated with the triad of “wacky, wet and wobbly”: Dementia, urinary incontinence and gait disturbance.
  • Dementia is often of the frontal or subcortical type, and initially primarily involves decrease in attention and executive function.
  • Urinary incontinence results from detrusor overactivity, sometimes combined with the patient having difficulty making it to the restroom in time because of gait problems.
  • Gait is generally slow, wide-based and shuffling. Falls are common.
  • Diagnosis is made by the presence of ventricular enlargement on imaging (defined as an Evans’ Index of at least 0.3), gait disturbance and either urinary incontinence. CSF opening pressures should be between 70 and 245 mm of H2O.
  • Evans’ Index: The maximum width of the frontal horns of the lateral ventricles divided by the largest biparietal distance.



Final Thoughts
Normal pressure hydrocephalus is generally considered a chronic condition, and the diagnosis is most often considered in the outpatient setting. However, this case serves as a reminder that the differential diagnosis for any emergent problem should include both acute conditions and exacerbations of chronic diseases. This is especially relevant when considering a patient who is traveling and outside of his familiar environment.


Sources
Graff-Radford, NR. “Normal pressure hydrocephalus.” http://www.uptodate.com. April 10, 2012.
Shprecher D, Schwalb J, and Kurlan R. “Normal Pressure Hydrocephalus: Diagnosis and Treatment.” Curr Neurol Neurosci Rep. 2008 September; 8(5): 371-376.



Every month during director’s rounds, our students present interesting and educational cases. This is a synopsis of the case voted to be the best by the students and directors at the end of director’s rounds along with an interesting image.


OR


Medical Student Program Directors

Jamie Edelstein, MD and Chen He, MD
slredmedstuds@gmail.com

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