STEALTH VIRAL ENCEPHALOPATHY:
Clinical and Diagnostic Assessment
Clinical and Diagnostic Assessment
Stealth viral encephalopathy is an organic brain disease which can manifest with a wide variety of clinical symptoms and syndromes. Patients with this disease will usually show discernable defects in various brain functions, together with non-neurological signs and symptoms of a systemic viral infection. This review provides general guidelines for the clinical and laboratory assessment of patients with stealth viral encephalopathy. Quantifying the various defects seen in the patients can help in monitoring the efficacy of therapy.
Stealth Viruses
The term stealth refers to cytopathic viruses which avoid confronting the cellular immune system because they lack genes coding for antigens required to evoke effective anti-viral cellular immunity. Consequently, stealth viruses can establish persistent infections in the absence of an inflammatory reaction. While stealth viral infections can cause widespread limited damage throughout many organs of the body, their effects are particularly noticeable when infection involves portions of the brain. As discussed elsewhere, the brain is particularly susceptible to stealth viruses because of the spatial diversity of its functions, such that localized damage can not be compensated by heightened activity elsewhere in the brain.
Clinical Evaluation:
The clinical history should focus on the onset of the patient's illness, the occurrence of illness in family members, friends and household pets and the factors which exacerbate or alleviate symptoms. The prior medical history and a history of family illness should be considered mainly in the context of a predetermined susceptibility of the patient to certain personality changes and specific cognitive impairments. A detailed description of present symptoms is useful in helping to focus the neuropsychological examination. Symptoms that may be present include the following neuropsychological symptoms:
Alterations in smell, taste, vision, hearing, touch, pain Unusual emotional reactions to sensory inputs Impaired sleep cycle, unusual vivid dreams, Personality changes, blunted affect, depression, attention deficit, agitationaranoid concerns, feelings of vulnerability, changes in feelings about others Impaired description and awareness of self Absence spells, actual seizures Memory loss, word searching and word use difficulty Nocturnal urination Episodes of unexplained perspiration, palpitations, diarrhea Unsteadiness of balance, walking or running
The neurological evaluation is structured to detect objective findings of autonomic, sensory, motor and higher level brain dysfunction. Individual patients will differ in the overall manifestations of their illness and the actual symptoms and signs will also vary over time. The following basic tests should be performed:
Autonomic Nervous System:
Blood pressure and pulse rate instability comparing supine and standing positions and following brief exercise and the Valsalva maneuver Temperature readings outside of normal range, also unstable temperatures taken by the patient at 4 hr. intervals during the day. Perspiration or excessive dryness of skin, hair Exaggerated "startle reflex"
Sensory Nervous System:
Pupil abnormalities, uneven, irregular, delayed response to light & accommodation, hippus Photophobia with squinting to light Diplopia especially with close objects moving to and from the face Nystagmus, restricted upward gaze Weakened ability to maintain shut eyelids, twitching of eyelids, delayed blink response Limited integration of items seen with peripheral vision with and without eye movement Impaired hearing of tuning fork ( tinnitus), defective localization of source of soun Difficulty with balance (one foot Romberg test), gait Reduced peripheral sensation to touch, pain, temperature, vibration and position
Motor Nervous System:
Motor response slowing, clumsiness, loss of precision of fine motor skills, unsteady gait Impaired finger-nose pointing and finger-finger touching especially when unseen Muscle tremor, fasciculation or wasting Limited control of facial expression Uneven chewing and swallowing (also note dry mouth, evidence of crimson crescents)
Higher Level Functions:
Altered or atonal voice, lessened ability to sing and/or reproduce notes Defects in three dimensional reconstruction, e.g., drawing Difficulties in word searching, word recognition, calculations, short term memory
Physical Findings Supportive of Viral Infection and/or Immune Activation:
Lymphadenopathy, salivary gland enlargement Gingivitis, crimson crescents in mouth Dry eyes, keratitis Skin rashes, loss of fingerprints, smooth and/or tight skin, hair loss Allergy, sinusitis Fibromyalgia tender points, myalgia, arthralgia, joint swelling, nodules
LABORATORY TESTING
1. Direct evidence of viral infection
Comprehensive viral cultures including detection of stealth viruses
(Yellow top tube of blood, CSF, material from vesicular skin lesions)Serology for activation of the following viruses
Polymerase chain reaction (PCR) for viruses detectable by culture or serology
2. Tests for immune activation
Flow cytometry of lymphocytes using activation markers Natural killer cell assays Serum immunoglobulin, C3,C4 C1Q complexes Protein electrophoresis Immune complex assays, cryoglobulin Interferon
3. Tests for endocrine dysfunction
Thyroid T3, T4, TSH Cortisol, DHEA, Melatonin (am and pm ) Serum and urine glucose, urine osmolarity
4. Tests for liver, kidney, and bowel dysfunction
Liver function tests, detoxification profiles to acetaminophen challenge Cholesterol, homocysteine, albumin Serum creatinine Steatorrhea, xylose absorption
5. Tests for autoimmunity
Anti-nuclear panel, ANA, anti-mitochondrial, anti-smooth muscle Anti-thyroid microsomal antibodies Anti-neuronal antibodies Anti-myelin antibodies Anti-adrenal antibodies
PHYSICAL EXAMINATION
Blood pressure and pulse rate measurements:
Diastolic Systolic Pulse Supine Standing Valsalva Eye Examination: Pupil Size: L =, <, > R; Constricted, Normal or Dilated; Even or Uneven Responses to light: Brisk or delayed; Hippus; Photophobia Response to accommodation: Brisk or delayed, Bilateral Diplopia on accommodation to objects moving to and from face Upward gaze: Normal or restricted Lateral gaze: Normal or restricted; Nystagmus Lateral fields of vision: Normal or restricted Dryness of Eyes Eyelids: Twitching Power to remain shut Blink response
Hearing and Balance Examination
Tinnitus Hearing of tuning fork Localization of source of sound Foot to toe walking Romberg test on one foot
Examination of Mouth and Nose
Dryness Reddness of fauces, salivary duct openings, gingivitis Soft palate movement Gag reflex Swallowing Smell Garlic Curry Secondary effects
Motor Control
Clumsiness five finger precision using both hands Finger to finger touching when unseen Fasciculation tremor wasting Object recognition
Systemic signs of infection/immune activation
Lymphadenopathy neck axilla Skin rash or other lesions Finger prints Tender points arthralgia
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