Endocrine and Neurological Disorders

SIADH vs. DI

SIADH (Syndrome of Inappropriate Antidiuretic Hormone Secretion)

• Pathophysiology: Too much antidiuretic hormone (ADH).
• Effect: Water retention leading to hyponatremia (low sodium levels in the blood).
• Labs:
  • Serum Sodium (Na): Low
  • Urine Osmolality: High
• Treatment:
  • Fluid restriction.
  • Hypertonic saline.
  • Demeclocycline.
• Contraindications:
  • No hypotonic fluids.
  • No thiazide diuretics.

DI (Diabetes Insipidus)

• Pathophysiology: Not enough ADH.
• Effect: Large, dilute urine output leading to hypernatremia (high sodium levels in the blood).
• Neurological Symptoms: Seizures.
• Treatment:
  • Desmopressin.
  • Fluids.

Thyroid Function

Feedback Loop

• Hypothalamus releases Thyrotropin-Releasing Hormone (TRH).
• TRH stimulates the Pituitary gland to release Thyroid-Stimulating Hormone (TSH).
• TSH stimulates the Thyroid gland to produce Triiodothyronine (T3) and Thyroxine (T4).

Labs

• Hypothyroid:
  • \uparrow TSH (high TSH)
  • \downarrow T3/T4 (low T3 and T4)
• Hyperthyroid:
  • \downarrow TSH (low TSH)
  • \uparrow T3/T4 (high T3 and T4)

Grave's Disease (Hyperthyroid)

• Symptoms:
  • Exophthalmos (bulging eyes).
  • Increased heart rate.
  • Heat intolerance.
• Medications:
  • Propylthiouracil (PTU).
  • Methimazole.
  • Beta-blockers.

Hashimoto's (Hypothyroid)

• Autoimmune disorder.
• Medications:
  • Levothyroxine.

Myxedema

• Life-threatening hypothyroidism.

Cortisol Disorders

Cushing's Syndrome

• Pathophysiology: High cortisol levels.
• Symptoms:
  • Moon face.
  • Buffalo hump.
  • Striae (stretch marks).
• May have high Adrenocorticotropic hormone (ACTH) if the cause is pituitary.
• Labs:
  • \uparrow Na (high sodium).
  • \downarrow K (low potassium).
  • \uparrow Glucose (high glucose).

Addison's Disease

• Pathophysiology: Low cortisol and aldosterone levels.
• Symptoms:
  • Weakness.
  • Bronze skin.
  • Low blood pressure.
  • Salt craving.
• Treatment:
  • Hydrocortisone.
  • Fludrocortisone.

Musculoskeletal & Neuro

Fibromyalgia

• Symptoms:
  • Widespread pain.
  • Fatigue.
  • Cognitive fog.

Migraines

• Symptoms:
  • Pulsating pain.
  • Photophobia (sensitivity to light).
  • Nausea and vomiting.
• Treatment:
  • Triptans.
  • Rest in a dark room.

Tension Headache

• Symptoms:
  • Band-like tightness.
• Stress-related.

Ear & Eye Disorders

Otitis Media

• Symptoms:
  • Ear pain.
  • Fever.
  • Tugging at the ear.
  • Decreased hearing.

Meniere's Disease

• Symptoms:
  • Vertigo.
  • Tinnitus (ringing in the ears).
  • Hearing loss.
• Pathophysiology:
  • Increased fluid in the inner ear (endolymph buildup).

Glaucoma

• Pathophysiology:
  • Increased intraocular pressure (IOP) leading to peripheral vision loss.
• "Looking through a straw" Tunnel vision.

Cataract

• Blurred vision.

Macular Degeneration

• Affects central vision causing blind spots directly ahead, resulting in central vision loss.
• Education:
  • Smoking cessation.
  • Increase intake of leafy greens.

Retinopathy

• Diabetic Retinopathy:
  • Most common type.
• Retinal Detachment:
  • Caused by trauma.
  • Symptoms: floaters, curtain-like vision loss.
• Retinopathy of Prematurity:
  • Complication in infants born before 32 weeks or weighing less than 1500g.
  • Can lead to blindness if untreated.

Key Lab Values with Ranges and Interpretation

Cardiac Markers

ATI Tip: Troponin is the most specific indicator for MI. Always assess chest pain, SOB, or EKG changes together.

Electrolytes (CMP Panel)

Nursing Alert: Always monitor K+ and Mg2+ together – low Mg can prevent K+ correction.

Glucose-Related

Endocrine Panels