VAGUL NERVE STIMULATION THERAPY

VIJIT AGRAWAL, B.PharmPHARM.D 5th YEARJSSCP, MYSORE

LOCATION OF VAGUS NERVE

• The vagus nerve also called pneumogastric nerve or cranial nerve X.

• 80-90% of the nerve fibers in the vagus nerve are afferent (sensory) nerves communicating the state of the viscera to the brain.

Medulla 

Jugular foramen

Carotid sheath 

Internal carotid artery

Internal jugular vein

Head, to the neck, chest and abdomen,

Innervation of the viscera

VAGUS NERVE IS RESPONSIBLE FOR…

• Slowing Heart rate • Gastrointestinal peristalsis• Sweating• Quite a few muscle movements in the mouth,

including speech • Keeping the larynx open for breathing• It also has some afferent fibers that innervate the

inner (canal) portion of the outer ear, via the Auricular branch

WHAT DOES THE PULSE GENERATOR LOOKS LIKE ?

ON DEMAND MAGNET STIMULATION…

• Offers more control for patients and their families

• Initiates on demand stimulation– May abort or decrease

severity of seizures

–May improve postictal period

• Stops stimulation

–Acutely manage side effects

HOW VNS WORKS ?VNS Therapy is delivered by a pulse

generator—a device like a pacemaker

The pulse generator sends mild, intermittent pulses through a thin, flexible wire leading to electrodes attached to the left vagus nerve.

Because the Vagus nerve does not contain pain fibers, VNS Therapy is typically painless.

VNS Therapy is regular, automatic, and generally unnoticeable.

MECHANISM OF ACTION

• Alteration of norepinephrine release by projections of solitary tract to the locus ceruleus.

• Elevated levels of inhibitory GABA related to vagal stimulation.

• Inhibition of aberrant cortical activity by reticular system activation.

APPROVAL OF THERAPY

• In 1997, the United States Food and Drug Administration (FDA) approved the use of VNS as an adjunctive therapy for partial-onset epilepsy.

• In 2005, the FDA approved the use of VNS for treatment-resistant depression.

INDICATIONS

• Epilepsy• Depression• Various Anxiety Disorders• Alzheimer's Disease• Obesity• Migraines• Fibromyalgia• Tinnitus

SIDE EFFECTS

• Sleep Apnoea (Common)

• Alteration of voice(66%)

• Coughing(45%), • Pharyngitis(35%)• Throat pain(28%)• Hoarseness (very

common)

• Loud Snoring• Upper airway obstruction

(rare) • Reversible

bradyarrhythmias• Other nonspecific

symptoms such as headache, nausea, vomiting, dyspepsia, dyspnea and paresthesia.

VNS Therapy - A Unique safety profile

• More than 60,000 patients worldwide have been implanted with VNS.

• No known interactions with medications• No reported systemic neurotoxic effects, rash, renal

impairment, or bone marrow suppression• No increase in sudden, unexpected death in epilepsy• Gestational outcomes– Animal study has shown no evidence of impaired

fertility or harm to the fetus.

OBS STUDY BY HOSAIN etal in LGS

• AGE 4-14 ,• 13 PTS 52% reduction in seizure rate in 6

months.• 3 had >90% reduction • 2 had >75% reduction • 1 had >50% reduction

OBS STUDY BY PARKER etal

• 16 children with epileptic encephalopathy 50% red.

• In 1yr significant improvement in EEG, adaptive behaviour, QOL, language performance.

OBS STUDY BY PATWARDAN etal

• 38 children , 10-18 months follow up • Seizure reduction• Atonic-80%,• Absence -65%,• CPS-48%,• GTCS-45%