Medicine

It is the innermost part of the adrenal gland, consisting of chromaffin cells that secrete catecholamines, including epinephrine (adrenaline), norepinephrine (noradrenaline), and a small amount of dopamine, in response to stimulation by sympathetic preganglionic neurons.

Stem Breakdown:

Acute-onset left leg pain and coldness: This suggests a sudden loss of blood flow, which is concerning for an acute arterial occlusion.
Pale and pulseless leg: These findings confirm that the limb is ischemic due to an arterial blockage.
History of chronic atrial fibrillation: Atrial fibrillation increases the risk of thromboembolism, which can lead to arterial embolism.
Option Analysis:

A) Deep vein thrombosis: Deep vein thrombosis (DVT) affects the veins, not arteries, and typically causes swelling, pain, and warmth in the affected limb, not coldness or pulselessness.
B) Acute arterial embolism: This is the correct diagnosis. Davidson and Harrison explain that acute arterial embolism is a sudden blockage of an artery, often due to an embolus originating from the heart (e.g., in atrial fibrillation). The "5 Ps" of acute arterial occlusion are Pain, Pallor, Pulselessness, Paresthesia, and Paralysis.
C) Chronic venous insufficiency: Chronic venous insufficiency causes leg swelling, varicose veins, and skin changes, but it does not cause sudden limb ischemia or a pulseless leg.
D) Peripheral neuropathy: Peripheral neuropathy causes numbness, tingling, and weakness, but it does not cause acute pain or loss of pulses.

Reference: Davidson 23rd; P-841

Explanation: Endoscopy is the preferred investigation for diagnosis of peptic ulcer disease

Reference: Davidson 23rd, Fig. 21.7 (39 BCS Question)

Reference: Practical Manual in Clinical Medicine by Professor ABM Abdullah; P-165

Dengue Shock Syndrome
Clinical Signs of Dengue Shock Syndrome:
• Cool extremities, delayed capillary refill time
• Lethargy or restlessness (which may be a sign of reduced brain perfusion)
• Tachypnoea or Kussmaul's breathing
• Tachycardia, weak pulse
• Narrow pulse pressure: Pulse pressure ≤20 mmHg with increased diastolic pressure, e.g. 100/80 mmHg •
Hypotension by age, defined as systolic pressure <80 mmHg for those aged <5 years or 80 to 90 mmHg for older children and adults

Reference: Davidson 23rd; P-482
সলভ ক্লাসের জন্য আলোচনা পোস্ট দেখুন - [আলোচনা পোস্টের লিঙ্ক]

Reference: Davidson 23rd; P- 1150 (Box-26.1)

Chronic kidney disease (CKD) is the most common cause of secondary hyperparathyroidism. Davidson explains that in CKD, impaired phosphate excretion and decreased production of active vitamin D (calcitriol) lead to hypocalcemia, which stimulates parathyroid hormone (PTH) release. Harrison adds that secondary hyperparathyroidism is an adaptive response to maintain normal calcium levels but can lead to renal osteodystrophy if left untreated.

Explanation: coagulation screening tests are Platelet count, PT, APTT & Fibrinogen concentration

Tuberculoid leprosy, caused by Mycobacterium leprae, presents with few hypopigmented, anesthetic skin patches with well-defined borders due to a strong cell-mediated immune response. Nodular lesions are seen in lepromatous leprosy, not tuberculoid

Cushing’s disease (a pituitary ACTH-secreting adenoma) is the most common endogenous cause. However, overall, iatrogenic (exogenous steroids) is most common.

GeneXpert detects M. tuberculosis DNA and rifampicin resistance within 2 hours

Explanation: DNA replication occurs in S(synthesis) phase of cell cycle

Reference: Davidson 23rd; P-668

TSH receptor antibodies (TRAb), especially thyroid-stimulating immunoglobulins, are highly specific for Graves’ disease, driving hyperthyroidism. Anti-TPO and anti-thyroglobulin antibodies are more common in Hashimoto’s

Chronic liver disease (CLD) is a broad term encompassing various conditions leading to progressive liver damage. Decompensation signifies the failure of the liver to perform its essential functions, often leading to complications like ascites, hepatic encephalopathy, variceal bleeding, and spontaneous bacterial peritonitis (SBP). SBP is an infection of the ascitic fluid and is a serious complication of advanced CLD with ascites.

Reference: Davidson 23rd; P-825
সলভ ক্লাসের জন্য আলোচনা পোস্ট দেখুন - [আলোচনা পোস্টের লিঙ্ক]

Reference: Davidson 23rd; P-799

Stem Breakdown:

Recurrent episodes of chest pain, palpitations, and shortness of breath: These symptoms suggest a tachyarrhythmia, such as paroxysmal supraventricular tachycardia (PSVT).
ECG showing PSVT: PSVT is a common type of arrhythmia characterized by sudden onset and termination, often due to reentrant circuits in the atrioventricular (AV) node.
Option Analysis:

A) Beta-blockers: Beta-blockers can be used to control the rate in some arrhythmias, but they are not the first-line treatment for terminating acute PSVT episodes.
B) Adenosine: This is the correct answer. Davidson and Harrison recommend adenosine as the first-line treatment for acute PSVT because it temporarily blocks AV nodal conduction, terminating the reentrant circuit responsible for PSVT. It is highly effective and works within seconds.
C) Calcium channel blockers: Calcium channel blockers (e.g., verapamil, diltiazem) can be used to slow AV nodal conduction in PSVT, but they are typically second-line agents after adenosine.
D) Amiodarone: Amiodarone is used to treat ventricular arrhythmias and atrial fibrillation but is not the first-line treatment for acute PSVT. It has a longer onset of action compared to adenosine.

Generalised cortical atrophy, particularly in the hippocampus and temporal lobes, is the hallmark imaging finding in Alzheimer’s disease. Davidson explains that atrophy reflects the loss of neurons and synapses in affected brain regions. Harrison adds that MRI or CT imaging can help support the clinical diagnosis, but definitive diagnosis still relies on clinical features and histopathology, if available.

HBV is a major cause of HCC, especially in endemic regions. Cirrhosis of any cause increases HCC risk.

Chronic liver disease can lead to impaired bile production and fat-soluble vitamin (A, D, E, K) malabsorption. Vitamin K deficiency can cause coagulopathy.

Evidence of Plasma Leakage (key differentiating point between Dengue and Dengue Haemorrhagic Fever)
Rise in Hct.: 20% (eg. In children 35 → 42 and in adults 40→48)
• Circulatory failure: Cold/cold clammy skin, CRFT>2 Sec, tachycardia, weak pulse, narrow pulse pressure <20, hypotension.
• Fluid accumulation - Ascites/ Pleural effusions
• Albumin <3.5 gm/dl

Current guidelines for RA emphasize early and aggressive treatment with disease-modifying anti-rheumatic drugs (DMARDs), typically methotrexate, within 3 months of diagnosis. This "treat-to-target" strategy aims to achieve remission or low disease activity to prevent irreversible joint damage and improve long-term outcomes. Delaying DMARDs allows progression of structural damage.

Reference: Davidson 23rd; P-812
সলভ ক্লাসের জন্য আলোচনা পোস্ট দেখুন - [আলোচনা পোস্টের লিঙ্ক]

Ref: Davidson 23rd; P-928, box: 23.13

Explanation: The most common cause of hypocalcaemia is a low serum albumin with normal ionised calcium concentration. For details, please see Davidson 23rd, Box-18.33

Holter monitor (24–48-hour ECG) is the most useful initial test to capture intermittent arrhythmias causing palpitations. Echocardiogram assesses structural heart disease, thyroid function tests screen for hyperthyroidism, and chest X-ray is less relevant, but Holter monitoring directly correlates symptoms with rhythm changes.

The kidneys have a rich blood supply and receive approximately 20%–25% of cardiac output through the renal arteries, which arise from the abdominal aorta. The renal arteries undergo various subdivisions within the kidney, eventually forming interlobular arteries that run through the renal cortex. These eventually give rise to afferent glomerular arterioles that supply the glomeruli.

Explanation: Plasmodium falciparum is a Parasite

Basal cell carcinoma
The incidence of NMSC has increased dramatically in recent decades and basal cell carcinoma (BCC) accounts for more than 70% of cases. In Europe, the ratio of BCC to SCC is 4–5:1 in immunocompetent patients. It is a malignant tumour that rarely metastasises; it is thought to derive from immature pluripotent epidermal cells and is composed of cells with similarities to basal layer epidermis and appendages. Lesions typically occur at sites of moderate sun exposure, particularly the face, and are slow-growing. The incidence increases with age and males are more commonly affected. Lesions may ulcerate and invade locally; hence the term ‘rodent ulcer’.

 Common presentations of dissociative (conversion) disorder
 Gait disturbance  Loss of function in limbs  Aphonia
 Non-epileptic seizures  Sensory loss  Blindness

Reference: Davidson 23rd , Page : 1184
Explanation : Nihilistic delusion- My head is missing , I have no body or I am dead

Reference: Davidson 23rd; P-573

Explanation: Amoebiasis is caused by Entamoeba histolytica

DIC is a complex, acquired disorder characterized by systemic activation of blood coagulation, leading to widespread fibrin formation in the microvasculature. This results in both consumptive coagulopathy (depletion of clotting factors and platelets) and secondary fibrinolysis, manifesting clinically as both thrombosis and bleeding.

Reference: Davidson 23rd; P-429

Reference: Davidson 23rd, Box-21.78

Zinc plays a vital role in the development and function of immune cells, particularly T-lymphocytes. Severe zinc deficiency leads to thymic atrophy and impaired cell-mediated immunity, increasing susceptibility to infections.

Ref: Davidson 23rd; P- 959

Cholera is characterized by voluminous, watery diarrhea with a “rice-water” appearance (pale, milky fluid with flecks of mucus) due to massive fluid secretion in the gut caused by the cholera toxin.

The patient’s symptoms of morning stiffness, symmetrical small joint pain, and positive rheumatoid factor/anti-CCP antibodies are diagnostic of rheumatoid arthritis (RA), a chronic autoimmune connective tissue disorder causing synovial inflammation. RA can lead to joint destruction and systemic complications. Atlantoaxial subluxation is a serious complication due to synovial inflammation in the cervical spine, particularly at the C1-C2 vertebrae, leading to instability and potential spinal cord compression.