Cluster headache

A 35 year old male presents to the neurology clinic with severe episodic unilateral periorbital pain that began 48 hours ago. The pain is excruciating, stabbing, and rapidly reaches peak intensity, lasting 30 to 90 minutes per episode. He reports associated ipsilateral eye redness, lacrimation, nasal congestion or rhinorrhea, ptosis, and miosis during attacks. The episodes occur multiple times daily, often at the same time each day, especially at night, waking him from sleep. During attacks, he is restless and agitated, pacing around the room. He has experienced similar headaches in the past occurring in cycles lasting weeks to months, followed by months to years of remission. MRI of the brain is normal. Diagnosis?

Diagnosis is Cluster headache.

1. Definition

Cluster headache is a primary headache disorder within the trigeminal autonomic cephalalgias, characterized by severe unilateral orbital or periorbital pain with ipsilateral autonomic symptoms, occurring in cyclical cluster patterns.

2. Etiology

1. Exact cause is unknown
2. Involves:
• Trigeminal-autonomic reflex activation
• Hypothalamic dysfunction
• Trigeminovascular system activation
3. Risk factors:
• Male sex
• Smoking
• Alcohol use
4. Possible genetic predisposition

3. Pathophysiology

1. Activation of the trigeminovascular system → release of CGRP and other neuropeptides → vasodilation and pain
2. Activation of parasympathetic pathways via the sphenopalatine ganglion → ipsilateral autonomic symptoms
3. Hypothalamic dysfunction leads to:
• Circadian periodicity
• Nocturnal attacks
• Cluster pattern

4. Clinical Features

1. Severe unilateral periorbital, supraorbital, or temporal pain
2. Duration: 15 to 180 minutes
3. Frequency: 1 every other day up to 8 per day
4. Occurs in clusters lasting weeks to months, followed by remission

4.2 Associated Features

1. Ipsilateral autonomic symptoms:
• Lacrimation and conjunctival injection
• Nasal congestion or rhinorrhea
• Eyelid edema
• Ptosis and miosis
2. Behavioral feature:
• Restlessness and agitation
3. Distinguishing feature:
• Patients are restless, unlike migraine patients who prefer to lie still
4. Other features:
• Nocturnal attacks
• Circadian pattern
• Alcohol triggers attacks during active cluster periods

5. Diagnosis

1. Based on ICHD-3 clinical criteria
2. Requires:
• At least 5 attacks
• Typical pain characteristics
• Ipsilateral autonomic symptoms or restlessness
• Frequency 1 every other day to 8 per day
3. Neuroimaging:
• MRI is recommended to exclude secondary causes, especially in atypical presentations

6. Management

6.1 Acute Treatment

1. High-flow oxygen via non-rebreather mask
2. Subcutaneous sumatriptan
3. Intranasal triptans as alternatives

6.2 Preventive Treatment

1. Verapamil is first-line
• Requires ECG monitoring
2. Transitional therapy:
• Corticosteroids
• Greater occipital nerve block
3. Other options:
• Lithium
• Topiramate
• Melatonin

7. Key Clinical Insight

Severe unilateral orbital pain with ipsilateral autonomic symptoms, circadian pattern, nocturnal attacks, and restlessness strongly indicates cluster headache

8. Exam Level Pearls

1. Cluster headache causes the most severe primary headache pain
2. Patients are restless, unlike migraine
3. Occurs in circadian and cluster patterns
4. Alcohol triggers attacks during cluster periods
5. First-line acute therapy is high-flow oxygen and subcutaneous sumatriptan

Gilbert Syndrome

A 20 year old male presents with yellowing of the eyes for the past few days. He has no significant past medical history and reports recent stress due to examinations. Vital signs are stable. Physical examination reveals scleral icterus. Laboratory investigations show normal CBC, normal AST, ALT, and ALP, total bilirubin of 2.4 mg/dL, and direct bilirubin of 0.2 mg/dL. There is no evidence of hemolysis. Diagnosis?

Diagnosis is Gilbert syndrome.

1. Definition

Gilbert syndrome is a benign inherited disorder of bilirubin metabolism characterized by intermittent unconjugated hyperbilirubinemia in the absence of liver disease or hemolysis, due to reduced activity of the UGT1A1 enzyme.

2. Etiology

1. UGT1A1 gene promoter polymorphism (commonly UGT1A1*28)
2. Autosomal recessive inheritance with incomplete penetrance
3. Reduced hepatic bilirubin conjugation

3. Pathophysiology

1. UGT1A1 activity reduced to about one third of normal
2. Impaired glucuronidation of unconjugated bilirubin
3. Accumulation of indirect bilirubin
4. Normal liver histology
5. Serum bilirubin typically 1 to 4 mg/dL, may increase during stress

4. Clinical Features

4.1 Core Features

1. Mild intermittent jaundice, often scleral icterus
2. Unconjugated hyperbilirubinemia
3. Otherwise asymptomatic
4. Onset in adolescence or young adulthood
5. No hepatosplenomegaly

4.2 Precipitating Factors

1. Fasting
2. Stress
3. Illness or fever
4. Dehydration
5. Vigorous exercise
6. Sleep deprivation
7. Menstruation

5. Diagnosis

5.1 Laboratory Findings

1. Elevated unconjugated bilirubin
2. Normal direct bilirubin
3. Normal AST, ALT, ALP
4. Normal CBC, LDH, and reticulocyte count

5.2 Diagnostic Criteria

1. Isolated unconjugated hyperbilirubinemia
2. Normal liver function tests
3. No evidence of hemolysis
4. Intermittent jaundice triggered by stress or fasting

6. Differential Diagnosis

1. Crigler Najjar syndrome
2. Hemolytic anemia
3. G6PD deficiency
4. Hereditary spherocytosis

7. Management

1. No treatment required
2. Patient reassurance
3. Avoid unnecessary investigations
4. Avoid precipitating factors when possible

8. Key Clinical Insight

Young patient with mild intermittent jaundice, normal liver enzymes, and isolated indirect hyperbilirubinemia, especially triggered by stress or fasting, strongly indicates Gilbert syndrome

9. Key Exam Points

1. Most common inherited cause of unconjugated hyperbilirubinemia
2. UGT1A1 deficiency
3. Bilirubin usually less than 4 mg/dL
4. Normal liver enzymes
5. No hemolysis
6. Reduced glucuronidation may increase toxicity of drugs such as irinotecan

Intussusception

A 24 month old male child presents with intermittent severe abdominal pain and multiple episodes of vomiting over the past 8 hours. The pain is colicky, lasting a few minutes, resolving spontaneously, and recurring every 15 to 30 minutes. During episodes, the child draws his knees to his chest and cries intensely. His mother reports red, mucus-like stool (currant jelly stool) in the diaper. He had a recent viral illness one week ago. On examination, the child is irritable. The abdomen is soft with mild distension, and a sausage-shaped mass is palpable in the right upper quadrant. Abdominal ultrasonography shows a target sign. Diagnosis?

Diagnosis is Intussusception.

1. Definition

Intussusception is the telescoping of a proximal segment of intestine into a distal segment, leading to bowel obstruction and compromised blood supply.

2. Etiology

1. Idiopathic, most common in children
2. Hypertrophy of Peyer patches following viral infection
3. Pathologic lead points:
• Meckel diverticulum
• Polyps or tumors

3. Pathophysiology

1. Invagination of bowel leads to obstruction
2. Venous congestion causes edema
3. Progression to ischemia
4. Mucosal bleeding occurs
5. Formation of currant jelly stool

4. Clinical Features

4.1 Core Features

1. Intermittent colicky abdominal pain
2. Vomiting, initially non-bilious, later may become bilious
3. Currant jelly stool

Note: The classic triad is present in less than 40 percent of cases

4.2 Associated Features

1. Child draws knees to chest during pain
2. Sausage-shaped abdominal mass, usually in right upper quadrant
3. Lethargy or altered responsiveness
4. Dance sign, empty right lower quadrant, may be present but is not reliable
5. Often preceded by viral illness

5. Diagnosis

5.1 Imaging

1. Ultrasound, first-line investigation
• Target sign or donut sign
2. Abdominal X-ray
• May show bowel obstruction
• Used to assess for perforation

5.2 Key Diagnostic and Therapeutic Tool

1. Air (pneumatic) enema
• Confirms diagnosis
• First-line treatment

6. Management

6.1 Initial Stabilization

1. Intravenous fluids
2. Electrolyte correction
3. Nasogastric decompression if needed

6.2 Definitive Treatment

1. Air enema reduction, first-line
2. Surgical intervention if:
• Enema reduction fails
• Peritonitis
• Perforation
• Hemodynamic instability

7. Complications

1. Bowel ischemia and necrosis
2. Perforation
3. Peritonitis
4. Recurrence, occurs in approximately 5 to 10 percent

8. Key Clinical Insight

Young child, typically between 6 and 18 months, with intermittent colicky abdominal pain, knee-to-chest posture, currant jelly stool, and target sign on ultrasound strongly indicates intussusception

9. Exam Level Pearls

1. Intermittent colicky pain with knee-to-chest posture is classic
2. Currant jelly stool is a late finding
3. Ultrasound target sign confirms diagnosis
4. Air enema is diagnostic and first-line treatment
5. Lethargy can be a key presenting feature