# Clinical Cases: Neurological Examination and Localization

## Case 1: Right MCA Stroke with Classic Localization

### Patient Demographics
- **Age:** 68 years
- **Sex:** Male
- **Occupation:** Retired accountant

### Chief Complaint
"My left arm and leg stopped working, and I can't speak properly."

### History of Present Illness
The patient was eating breakfast when his wife noticed his face drooping on the left side. He dropped his coffee cup and was unable to lift his left arm. His speech became slurred and he had difficulty finding words. Symptoms onset was 2 hours ago. Past medical history includes hypertension, hyperlipidemia, and atrial fibrillation (not on anticoagulation).

### Neurological Examination Findings

**Mental Status:**
- Alert but frustrated
- Expressive aphasia - speaks in telegraphic phrases, good comprehension
- Oriented to person and place, difficulty with date

**Cranial Nerves:**
- Left lower facial droop (CN VII - UMN pattern: forehead spared)
- Left-sided neglect on visual fields
- Eyes deviated to the right
- Pupils equal and reactive

**Motor Examination:**
- Left upper extremity: 0/5 strength (flaccid initially)
- Left lower extremity: 2/5 strength
- Right side: 5/5 strength throughout
- Left pronator drift present

**Sensory Examination:**
- Decreased sensation to light touch and pinprick on left face, arm, and leg
- Extinction to double simultaneous stimulation on left

**Reflexes:**
- Left upper and lower extremity: 3+ (hyperreflexia developing)
- Left Babinski sign positive (upgoing toe)
- Right side: 2+ throughout

**Coordination:**
- Unable to assess left side due to weakness
- Right finger-to-nose and heel-to-shin normal

**Gait:**
- Unable to ambulate

### Localization
**Lesion Location:** Right middle cerebral artery (MCA) territory
- Left hemiparesis (contralateral motor cortex/internal capsule)
- Left facial droop with forehead sparing (UMN pattern - CN VII)
- Expressive aphasia suggests left hemisphere, but patient is left-handed
- Right gaze preference (frontal eye fields)
- Left-sided neglect (right parietal lobe)
- UMN signs (hyperreflexia, Babinski) = cortical/subcortical lesion

### Neuro Workup
- **NIHSS Score:** 14
- **CT Head without contrast:** Hyperdense right MCA sign, early loss of gray-white differentiation in right insula
- **CT Angiography:** Occlusion of right M1 segment of MCA
- **CT Perfusion:** Large ischemic penumbra with small core infarct
- **Labs:** INR 1.0, glucose 142, platelets 198K

### Diagnosis
**Acute right MCA ischemic stroke** secondary to cardioembolic source (atrial fibrillation)

### Management
1. IV alteplase (tPA) administered within 3-hour window
2. Mechanical thrombectomy performed - successful recanalization (TICI 2b)
3. Admit to Neuro ICU for blood pressure management
4. NPO until swallow evaluation
5. Initiate anticoagulation after 24-48 hours for secondary prevention
6. Physical therapy, occupational therapy, speech therapy consults
7. Risk factor modification: continue antihypertensives, statin

### Clinical Image
![Right MCA Stroke](case_01_image.jpg)

**Image Description:** CT angiography showing occlusion of the right middle cerebral artery (M1 segment) with absence of distal flow.

**Attribution:** Image from Radiopaedia.org, Case courtesy of Dr. Frank Gaillard. Licensed under CC BY-NC-SA 3.0. Source: https://radiopaedia.org/cases/mca-occlusion-ct-angiography

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## Case 2: Brown-Sequard Syndrome - Spinal Cord Hemisection

### Patient Demographics
- **Age:** 34 years
- **Sex:** Female
- **Occupation:** Construction worker

### Chief Complaint
"I can't feel temperature on my right leg, and my left leg is weak."

### History of Present Illness
The patient was involved in a workplace accident where a metal rod penetrated her upper back on the left side. She immediately noticed weakness in her left leg and an unusual sensation in her right leg. She describes that she cannot feel hot or cold on her right leg but can still feel touch. The left leg feels "normal" but won't move properly.

### Neurological Examination Findings

**Mental Status:**
- Alert, oriented, appropriate

**Cranial Nerves:**
- All cranial nerves intact (II-XII)

**Motor Examination:**
- Left lower extremity: 2/5 hip flexion, 3/5 knee extension, 2/5 ankle dorsiflexion
- Right lower extremity: 5/5 throughout
- Upper extremities: 5/5 bilateral

**Sensory Examination:**
- Left side: Loss of vibration and proprioception below T6 level
- Left side: Light touch intact
- Right side: Loss of pain and temperature below T8 level
- Right side: Vibration and proprioception intact

**Reflexes:**
- Left lower extremity: 3+ (hyperreflexia)
- Left Babinski positive
- Right lower extremity: 2+
- Right Babinski negative

**Coordination:**
- Impaired heel-to-shin on left (due to proprioceptive loss)
- Right side normal

### Localization
**Lesion Location:** Left spinal cord hemisection at T6 level (Brown-Sequard Syndrome)
- Ipsilateral (left) motor weakness - corticospinal tract
- Ipsilateral (left) loss of vibration/proprioception - dorsal columns
- Contralateral (right) loss of pain/temperature - spinothalamic tract (crosses 1-2 levels below entry)
- UMN signs ipsilaterally below lesion

### Neuro Workup
- **MRI Spine with contrast:** Left hemicord signal abnormality at T6 level with associated cord edema
- **CT Spine:** Metallic foreign body trajectory through left posterior elements at T6
- **Somatosensory evoked potentials:** Delayed responses from left lower extremity

### Diagnosis
**Traumatic Brown-Sequard Syndrome** at T6 level secondary to penetrating spinal cord injury

### Management
1. Emergent neurosurgical consultation for foreign body removal and decompression
2. High-dose methylprednisolone (controversial but considered)
3. Maintain spinal precautions
4. DVT prophylaxis
5. Foley catheter for neurogenic bladder
6. Aggressive rehabilitation program
7. Prognosis: Brown-Sequard has best prognosis among incomplete spinal cord injuries

### Clinical Image
![Brown-Sequard Syndrome](case_02_image.jpg)

**Image Description:** MRI T2-weighted image of the thoracic spine demonstrating hemicord hyperintensity consistent with cord contusion.

**Attribution:** Image from Wikipedia Commons, public domain. Source: https://commons.wikimedia.org/wiki/File:Brown-Sequard_syndrome.svg

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## Case 3: Cerebellar Lesion with Classic Findings

### Patient Demographics
- **Age:** 52 years
- **Sex:** Male
- **Occupation:** Carpenter

### Chief Complaint
"I'm dizzy and can't walk straight. My hand keeps missing things."

### History of Present Illness
Progressive symptoms over 3 weeks of worsening balance, difficulty with fine motor tasks (trouble using tools), and a sensation of the room spinning. He has also noticed morning headaches and nausea. No hearing loss or tinnitus. Past medical history significant for lung cancer diagnosed 6 months ago.

### Neurological Examination Findings

**Mental Status:**
- Alert, oriented x3
- Speech: Scanning dysarthria (irregular rhythm, explosive quality)

**Cranial Nerves:**
- Nystagmus: Horizontal, worse on right lateral gaze
- CN VI palsy on right (from increased ICP)
- Papilledema bilateral

**Motor Examination:**
- Strength 5/5 throughout bilateral upper and lower extremities
- No pronator drift
- Tone: Hypotonia right upper extremity

**Sensory Examination:**
- Intact to all modalities throughout

**Reflexes:**
- 2+ symmetric throughout
- Plantar responses flexor bilaterally
- Pendular reflexes on right

**Coordination:**
- Right finger-to-nose: Dysmetria (past-pointing) and intention tremor
- Right heel-to-shin: Marked dyssynergia
- Rapid alternating movements: Dysdiadochokinesia on right
- Rebound phenomenon positive on right

**Gait:**
- Wide-based, ataxic gait
- Tendency to fall to the right
- Unable to perform tandem gait

### Localization
**Lesion Location:** Right cerebellar hemisphere
- Ipsilateral limb ataxia (dysmetria, dysdiadochokinesia, intention tremor)
- Hypotonia ipsilaterally
- Scanning dysarthria
- Nystagmus with fast phase toward lesion
- Wide-based gait with tendency to fall toward lesion side
- Note: Cerebellum = ipsilateral findings (unlike cerebral hemispheres)
- Signs of increased ICP: headache, papilledema, CN VI palsy

### Neuro Workup
- **CT Head:** 3.5 cm hyperdense mass in right cerebellar hemisphere with surrounding edema and early hydrocephalus
- **MRI Brain with contrast:** Enhancing mass in right cerebellar hemisphere, likely metastatic disease
- **MRI complete spine:** No spinal metastases
- **LP:** Contraindicated due to mass effect

### Diagnosis
**Right cerebellar metastasis** from primary lung cancer with associated obstructive hydrocephalus

### Management
1. Dexamethasone 10mg IV then 4mg q6h for vasogenic edema
2. Neurosurgery consultation for possible resection vs. shunting
3. Radiation oncology consultation for stereotactic radiosurgery vs. whole brain radiation
4. Oncology follow-up for systemic therapy
5. Fall precautions
6. Physical therapy for balance training
7. Palliative care involvement for goals of care discussion

### Clinical Image
![Cerebellar Metastasis](case_03_image.jpg)

**Image Description:** MRI T1-weighted with contrast showing an enhancing mass in the right cerebellar hemisphere consistent with metastatic disease.

**Attribution:** Image from Radiopaedia.org, Case courtesy of Dr. Matt Skalski. Licensed under CC BY-NC-SA 3.0. Source: https://radiopaedia.org/cases/cerebellar-metastasis-1