# Clinical Cases: Cerebrospinal Fluid and Ventricles ## Case 1: Normal Pressure Hydrocephalus ### Patient Presentation **Demographics:** 74-year-old male **Chief Complaint:** Progressive difficulty walking and memory problems over 6 months **History of Present Illness:** The patient's wife reports that her husband has had increasingly unsteady walking over the past 6 months. He shuffles his feet and has fallen twice, once in the bathroom and once trying to walk to the kitchen. She also notes he has become forgetful, especially for recent events, and seems "slowed down" mentally. Over the past 2 months, he has had several episodes of urinary incontinence, which is new for him. He attributes it to "not making it to the bathroom in time." There is no history of headaches, vision changes, or recent head trauma. **Physical Examination:** - Vital signs: BP 138/82, HR 68, T 36.8C - General: Pleasant elderly male, appears his stated age - Neurological: - Mental status: Oriented to person and place, knows the month but not the date; slow to respond; scores 22/30 on MoCA (impaired in delayed recall and executive function) - Cranial nerves: Intact - Motor: 5/5 strength throughout; no rigidity - Sensory: Intact to light touch and vibration - Reflexes: 2+ throughout, Babinski absent bilaterally - Gait: Wide-based, shuffling gait with short steps; appears as if feet are "stuck to floor" (magnetic gait); difficulty initiating steps; no arm swing; cannot perform tandem walk **Workup:** - **CT head:** Ventriculomegaly with disproportionate enlargement of ventricles compared to sulci; Evans ratio 0.38 (>0.30 indicates ventriculomegaly); no periventricular edema - **MRI brain:** Enlarged ventricles out of proportion to cortical atrophy; no parenchymal lesions; aqueduct patent; some flow void present - **Large-volume lumbar puncture (tap test):** Opening pressure 170 mm H2O (upper normal); 40 mL CSF removed; protein and glucose normal; no cells - **Post-LP gait assessment:** Significant improvement in gait 4 hours after LP - shorter steps replaced by near-normal stride, reduced shuffling, able to turn more easily **Diagnosis:** Idiopathic normal pressure hydrocephalus (iNPH) **Treatment:** - Ventriculoperitoneal (VP) shunt placement with programmable valve - Physical therapy for gait training - Occupational therapy for cognitive strategies **Clinical Course:** Two weeks after VP shunt placement, the patient's wife reported dramatic improvement in walking. He was no longer shuffling and had not fallen. Urinary urgency improved significantly, though he still had occasional accidents if he delayed going to the bathroom. Cognitive testing at 3-month follow-up showed improvement in MoCA score to 26/30. At 6-month follow-up, he was living independently with his wife and participating in daily activities. **Clinical Pearl:** The classic triad of NPH is "wet, wacky, and wobbly" - urinary incontinence, dementia, and gait apraxia. The gait disturbance is typically the earliest symptom and most responsive to treatment. The "tap test" (large-volume LP with pre- and post-assessment) helps predict shunt response. Unlike other causes of ventriculomegaly, NPH shows disproportionate ventricular enlargement compared to sulcal widening, distinguishing it from ex vacuo hydrocephalus due to atrophy. --- ## Case 2: Obstructive Hydrocephalus from Colloid Cyst ### Patient Presentation **Demographics:** 42-year-old female **Chief Complaint:** Sudden severe headache with nausea and transient loss of consciousness **History of Present Illness:** The patient was at work when she suddenly developed an extremely severe headache, "the worst of her life." She became nauseated and vomited twice. Coworkers noted she appeared confused and then briefly lost consciousness for approximately 30 seconds. She was responsive when EMS arrived but complained of persistent severe headache and photophobia. She has no significant past medical history. Her mother died suddenly at age 47 from a "brain problem" - specific details unknown. **Physical Examination:** - Vital signs: BP 172/98, HR 58, T 37.2C - General: Eyes closed, prefers dark room, holding her head - Neurological: - Mental status: Alert but slow to respond; oriented to person and place but not date - Cranial nerves: Pupils equal and reactive but sluggish; fundoscopic exam shows early papilledema bilaterally; no other cranial nerve deficits - Motor: 5/5 throughout; moves all extremities - Reflexes: 2+ and symmetric - Neck: Supple (no meningismus) **Workup:** - **CT head without contrast:** Markedly dilated lateral ventricles bilaterally; third ventricle not visualized; round hyperdense lesion at the foramen of Monro measuring 1.5 cm; no blood in subarachnoid spaces - **MRI brain:** Well-circumscribed cystic lesion at the foramen of Monro with high T1 and T2 signal (proteinaceous content), consistent with colloid cyst; bilateral lateral ventricular dilatation; third ventricle collapsed - **Lumbar puncture:** Deferred given obstructive hydrocephalus and risk of herniation **Diagnosis:** Obstructive hydrocephalus secondary to third ventricular colloid cyst **Treatment:** - Urgent neurosurgical consultation - Dexamethasone for cerebral edema - External ventricular drain (EVD) placed emergently for ICP management - Endoscopic surgical resection of colloid cyst performed on hospital day 2 **Clinical Course:** Following EVD placement, the patient's headache improved significantly. Surgical resection was successful with complete removal of the cyst. The EVD was weaned and removed on post-operative day 3. Repeat imaging showed decompressed ventricles. At 2-week follow-up, she was asymptomatic with normal neurological examination. **Clinical Pearl:** Colloid cysts are benign, slow-growing lesions that arise in the anterior third ventricle at the foramen of Monro. They can cause sudden obstruction of CSF flow (ball-valve mechanism), leading to acute obstructive hydrocephalus with rapid rise in ICP. The sudden onset of severe headache with obtundation can mimic subarachnoid hemorrhage. Acute presentation can be fatal if not recognized and treated emergently. Positional changes may precipitate symptoms as the cyst moves within the ventricle. --- ## Case 3: Idiopathic Intracranial Hypertension (Pseudotumor Cerebri) ### Patient Presentation **Demographics:** 28-year-old female **Chief Complaint:** Daily headaches and "vision going gray" for 3 weeks **History of Present Illness:** The patient reports daily throbbing headaches for the past 3 weeks, worse in the morning and when bending over. She has noticed episodes where her vision "grays out" for a few seconds when standing up or straining. She hears a "whooshing" sound in her right ear that pulses with her heartbeat. She has also had intermittent double vision when looking to the side. Her weight is 118 kg (BMI 42). She started a new oral contraceptive 2 months ago. She denies history of similar symptoms. **Physical Examination:** - Vital signs: BP 126/78, HR 72, T 36.9C - General: Obese female in no acute distress - Neurological: - Mental status: Alert, oriented, normal cognition - Cranial nerves: - Visual acuity: 20/20 OU - Visual fields: Enlarged blind spots bilaterally on confrontation - Fundoscopy: Bilateral papilledema with blurred disc margins, venous engorgement, and loss of spontaneous venous pulsations - Bilateral sixth nerve palsies with limited abduction - Other cranial nerves normal - Motor/Sensory/Reflexes: Normal - Gait: Normal **Workup:** - **MRI brain with MRV:** No mass lesion; flattening of posterior sclera bilaterally; partially empty sella; tortuous optic nerve sheaths; patent venous sinuses - **Lumbar puncture:** Opening pressure 350 mm H2O (markedly elevated; normal <200); CSF composition completely normal (protein 22, glucose 65, no cells) - **Visual field testing:** Enlarged blind spots bilaterally; early peripheral constriction - **Optical coherence tomography (OCT):** Increased retinal nerve fiber layer thickness consistent with papilledema **Diagnosis:** Idiopathic intracranial hypertension (IIH) **Treatment:** - Acetazolamide 500 mg twice daily, titrated to 1000 mg twice daily - Discontinuation of oral contraceptive - Referral to weight management/bariatric surgery consultation - Serial visual field testing and OCT monitoring - Therapeutic lumbar puncture performed during diagnostic LP (30 mL removed) **Clinical Course:** After 2 weeks of treatment, the patient reported significant headache improvement. At 1-month follow-up, papilledema had improved, and visual fields showed reduced blind spot enlargement. She lost 8 kg with dietary changes. At 6-month follow-up, she had lost 25 kg total, papilledema had resolved, and acetazolamide was being tapered with plan for eventual discontinuation. **Clinical Pearl:** IIH classically affects obese women of childbearing age. The transient visual obscurations are concerning and indicate optic nerve compromise from elevated pressure. Untreated, IIH can lead to permanent vision loss from optic nerve damage. The key diagnostic criteria are elevated ICP (>250 mm H2O), normal CSF composition, and no structural cause on imaging. MRI signs include empty sella, flattened posterior globes, and tortuous optic nerves. Weight loss is the most effective long-term treatment. --- ## Clinical Image ![Hydrocephalus CT scan](case_01_image.jpg) **Image Description:** Axial CT scan demonstrating hydrocephalus with marked dilation of the lateral ventricles. The temporal horns are prominently enlarged, the frontal horns are ballooned, and periventricular hypodensity may be visible representing transependymal CSF flow. The Evans ratio (ratio of maximum width of frontal horns to maximum internal skull diameter) can be calculated to quantify ventriculomegaly. **Attribution:** Image from Radiopaedia (https://radiopaedia.org/), Creative Commons Attribution-NonCommercial-ShareAlike 3.0 license.