Does PCP cause nystagmus?
A large case series demonstrated nystagmus in 57% of patients with PCP intoxication, although smaller studies have found an incidence of 85% or higher. Many CNS depressants can produce nystagmus when taken in high doses; however, the patient is generally sedated when nystagmus is observed.
What drug can cause vertical nystagmus?
The most common drug/toxin overdoses that cause nystagmus are the following:
- Anticonvulsants (phenytoin, carbamazepine, valproic acid, lamotrigine, topiramate)
- Phencyclidine (PCP)
- Lysergic acid diethylamide (LSD)
What is PCP toxicity?
The usual street dose of PCP is 1-6 mg and results in mild intoxication. Larger ingestions (6-10 mg) can cause toxic psychoses and signs of sympathetic hyperactivity, including hypertension, rigidity, hyperthermia, tachycardia, and seizure. Very large doses (≥ 200 mg) can result in death.
How does PCP affect the central nervous system?
Phenycyclidine (PCP) produces many profound effects in the central nervous system. PCP has numerous behavioral and neurochemical effects such as inhibiting the uptake and facilitating the release of dopamine, serotonin, and norepinephrine. PCP also interacts with sigma, mu opioid, muscarinic, and nicotinic receptors.
What can cause vertical nystagmus?
Vertical nystagmus (downbeat and upbeat nystagmus) is typically caused by posterior fossa lesions. Other causes include medication side effects, vitamin deficiencies, inflammatory and autoimmune/paraneoplastic conditions, and hereditary and degenerative cerebellar ataxias.
What causes vertical gaze nystagmus?
Vertical Gaze Nystagmus is an involuntary jerking of the eyes (up and down) which occurs when the eyes gaze upward at maximum elevation. The presence of this type of nystagmus is associated with high doses of alcohol for that individual and certain other drugs.
What causes a vertical nystagmus?
Is vertical nystagmus central or peripheral?
Nystagmus that is purely horizontal, vertical, or torsional usually has a central cause.
Is vertical nystagmus bad?
CONCLUSIONS—Vertical and asymmetric nystagmus are most commonly associated with serious intracranial pathology and its presence is an indication for neuroimaging studies. However, such nystagmus can occur in children with retinal disease, albinism, and in cases with CIN.
Can you have vertical nystagmus?
What causes vertical nystagmus?
Can a PCP overdose cause vertical nystagmus?
PCP overdose causes combinations of muscle rigidity, characteristic bursts of horizontal and vertical nystagmus, stereotypies, and a blank stare. The muscle rigidity may evolve into rhabdomyolysis that mimics the neuroleptic malignant syndrome.
Is there a 1 St law for BPPV nystagmus?
Often times, practitioners new to BPPV are perplexed when they begin see their first PC-BPPV patients after learning in their lectures about “rotary-torsional” nystagmus. It is important to remember Ewald’s 1 st Law. Simply put, vertical canal BPPV produces vertical nystagmus.
Which is the correct description of vertical nystagmus?
Vertical nystagmus may be either upbeating or downbeating. When present in the straight-ahead position of gaze (i.e. the primary position) it is referred to as ‘upbeat nystagmus’ (UBN) or ‘downbeat nystagmus’ (DBN) ( Leigh and Zee, 1999 ). DBN is usually greater on looking laterally or in downgaze, whereas UBN often increases on upgaze.
Is the nystagmus a rotary or torsional movement?
The nystagmus, while described as “rotary-torsional”, will actually have a more visible upward and oblique movement than may be anticipated by new practitioners. Often times, practitioners new to BPPV are perplexed when they begin see their first PC-BPPV patients after learning in their lectures about “rotary-torsional” nystagmus.