PSYCHOSIS INTERMITTENT HYPONATREMIA, AND POLYDIPSIA SYNDROME

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วิญญู ชะนะกุล สถาบันจิตเวชศาสตร์สมเด็จเจ ้าพระยา

Outline      Definition Prevalence Etiology Diagnosis Management

Definition  Polydipsia  Primary /psychogenic polydipsia  Secondary------DI,DM,medications  Hyponatremia  Water intoxication

Hyponatremia  Plasma Na + below 135 mMol/L

Water intoxication  = SYMPTOMATIC HYPONATREMIA

Water intoxication      Diarrhea-------hypotonic rehydration Marathon runners Drinking contest Iatrogenic PIP

polydipsia hyponatremia Water intoxication

Psychosis intermittent hyponatremia, and polydipsia syndrome      Compulsive water drinking Psychogenic polydipsia Self-induced water intoxication Without any organic disease Normal renal function

Prevalence     3-40 % in chronic psychiatric inpatients 80 % are schizophrenia 10 % are organic mental disorder 5 % had episodes of water intoxication

Normal adaptaion  Thirst center  AVP (ADH)  Brain volume regulation

Etiology    Hypothalamic defect Abnormal regulation of thirst +- SIADH

Associated factors         Male gender Caucasian Schizophrenia /mental retardation Chronicity of psychiatric disorder Negative symptoms Disorganized symptoms General symptoms of psychopathology Smoking

Risk of water intoxication in polydipsic patients  Rapidity  Severity

Pathophysiology      Polydipsia Decrease plasma osmolality ECF ICF Brain edema Brain herniation

Abnormal adaptaion  Thirst center +- AVP (ADH)  Brain volume regulation

Signs and symptoms  Simple polydipsia with polyuria  water seeking behavior  Polydipsia with water intoxication ( hyponatremic encephalopathy )

Signs and symptoms

Somatic symptoms

        Nausea/vomitting Headache Confusion Delirium Ataxia Seizure Coma Death

Psychiatric symptoms

  Agitation Irritability

Signs and symptoms  Chronic hyponatremia  ataxia/ fall  subtle cognitive impairment

diagnosis  No diagnostic standard

Measurement  Biological measure  Urine specific gravity  Diurnal weight gain  Urine osmolarity  Behavioral measure

Differential diagnosis hypovolemic • Diuretics(renal loss) • Diarrhea (extra renal loss) euvolemic • PIP • SIADH • Hypothyroid hypervolemic • CHF • Cirrhosis • Nephrotic syndrome,renal failure

Management  Identify risk  Multidisciplinary approach  Biopsychosocial approach

Multidisciplinary approach แพทย์ • Differential diagnosis • Treat hyponatremia,medications พยาบาล • Evaluate self-care • Water restriction,education นักจิตวิทยา • Evaluate psychological function • Behavioral intervention นักสังคม • Evaluate social function • Discharge planning,care giver

Treatment  Acute treatment  Long-term treatment

Acute treatment      Water restriction Increase renal free-water excretion Na+ replacement Supportive treatment Symptomatic treatment

Acute treatment    Fluid restriction Diuretics Salines -- 3%NaCl

Goal of acute treatment  1. symptoms are abolished  2. safe plasma Na + ( > 120mmol/l)  3.

not more than 10-12 mmol/l/day

Long-term treatment     Salt -added diet Medications Voluntary water restraint Involuntary water restriction

Medications          Lithium Phenytoin Naloxone Propanolol Enalapril Clonidine Vasopressin receptor antagonist Clozapine Risperidone

Behavioral approach    Relaxation Stimulus control   Self-Monitoring  distract / substitute Coping skill Reinforcement