Showing posts with label Dizziness. Show all posts
Showing posts with label Dizziness. Show all posts

Sunday, April 29, 2012

Steroids for Dizziness Too

Motivation:  During my final rotation in the ED, I met surprisingly many patients with sudden onset of severe unrelenting dizziness - chalked up to vestibular neuritis after clean MRI.  Besides sympathetic listening and symptomatic control with meclizine, is there anything else to do?  I had thought not.  I recently found out, however, that steroids can help vestibular neuritis too.  How good is the data?

For background, the cause of vestibular neuritis is not definitely known but based on associational data, appears related to viral infection or reactivation of latent HSV1.  Symptoms of dizziness usually last three to seven days but recovery is often incomplete with many patients having persistent vestibular deficits on exam.

Paper: Strupp, M., Zingler, V.C., Arbusow, V. et. al.  "Methylprednisolone, Valacyclovir, or the Combination for Vestibular NeuritisN. Engl. J. Med. (2004) 351: 354-61.

Methods: A prospective, randomized, double-blind, 2x2 factorial trial testing methylprednisolone and valacyclovir in patients with acute vestibular neuritis.  Adult patients were recruited through ED in academic hospitals in Munich and Mainz, Germany.  Diagnosis of vestibular neuritis was based on history of acute onset of severe prolonged vertigo with exam showing unidirectional horizontal nystagmus with a rotational component.  Patients were primarily excluded if they had additional cochlear symptoms (tinnitus or hearing loss), other brainstem deficits, central lesions on MRI, or contraindications to steroids or valacyclovir (peptic ulcer disease, osteoporosis, renal failure, liver injury, etc.).  Methylprednisolone was dosed at 100 mg on first three days with a prolonged taper ending at 10 mg on day 22.  Valacyclovir was dosed at 1000 mg three times daily for seven days.  Primary outcome was vestibular paresis at 12 months.

Results:
Cohort: In total, 141 patients were randomized - 38 to placebo, 35 to methylprednisolone, 33 to valacyclovir, and 35 to steroid plus valacyclovir.  Baseline characteristics were balanced, and average age was in late 40s for most groups.  Treatment was started on average 1.6 to 1.8 days after onset of symptoms.  Follow-up data present for 30/38 in placebo, 29/35 in steroids, 27/33 for valacyclovir, and 28/35 for steroid plus valacycolvir group.  Most common reason for withdrawing was unwillingness to follow-up or non-compliance.

Efficacy Measurement: Change in vestibular function over time was measured by assessing nystagmus in response to caloric stimulation (warm water) in the ears.  Intact vestibular response leads to appropriate nystagmus while damaged vestibular system leads to relative paresis.  Analysis was by as treated and not by intention to treat population.

Steroid: At 12 months, patients receiving methylprednisolone had 62.4% improvement in vestibular function compared to 39.6% improvement with placebo (p<0.001).

Valacyclovir: At 12 months, patient receiving valacyclovir had 36% improvement in vestibular function compared to 39.6% improvement with placebo (not significant).  Combination of steroid and valacyclovir resulted in 59.2% improvement in vestibular function, but the improvement was not significantly different from that achieved by steroids alone.

Discussion:  This trial demonstrates that acute treatment of vestibular neuritis with corticosteroids may help prevent long-term vestibular damage.  Interestingly, the authors did not track resolution of vertigo - the primary symptom that brought the patients in.  The authors intentionally did not track vertigo because they assumed that the brain would compensate centrally for the imbalanced input from the two ears after a few days.  Symptom improvement would not correlate with actual recovery of the vestibular system, but it would have been nice to have the data to compare.  The trial also shows that valacyclovir treatment really did not affect the long-term outcome.  The reason could either be that vestibular neuritis is usually not HSV mediated or that the actual reactivation and replication occurred prior to symptoms and initiation of treatment with valacyclovir.  While convincing, this trial has some serious limitations including small number of subjects, no intention to treat analysis, and significant number of patients lost to follow-up in each group (17% dropout rate in steroid group).  This data needs to be backed up with a larger trial.  For now, though, for patients with acute vestibular neuritis with no contraindications to steroids, starting treatment early may likely have long-term beneficial effects.

Tuesday, January 17, 2012

Dizzy is dizzy

Motivation: During patient presentations, saying that a patient is "dizzy" without further qualifiers is sure to trigger further questions.  Did dizziness actually mean vertigo or fainting ("presyncope") or unsteadiness?  This approach to dissecting dizziness into further subdivisions stems from a 1972 paper which divided dizziness into vertigo, presyncope, disequilibrium, and "vague lightheadedness," with the implication that vertigo stems from vestibular causes, presyncope from cardiovascular causes, disequilibrium from neurological causes, and other dizziness from other causes.  This approach, while never rigorously validated, has permeated medicine and has almost become the standard framework for evaluating dizziness.  Recently, this approach has been questioned with growing evidence that the various subtypes of dizziness have many overlapping etiologies.

Results:  Unlike other posts, I will summarize three articles here that show that the approach of subdividing dizziness may not be valid because many dangerous causes of dizziness have variable presentations.

1. Culic, V., Miric, D. and Eterovic, D. "Correlation between symptomatology and site of acute myocardial infarction." Int. J. Cardiol. (2001) 77: 163-8:

In this paper, the authors attempted to correlate sites of myocardial infarction and symptoms of presentation among 1546 patients.  Among the many symptoms, the authors separated feeling of "vertigo" from "faintness."  Here are the findings:

SITE OF INFARCTION                   % WITH VERTIGO             % WITH FAINTING
      Anterior                                               11.1                                   6.2
      Inferior                                                  4.7                                    4.9
      Lateral                                                  8.3                                    4.2

 
2. Newman-Toker, D.E. and Camargo, C.A. "Cardiogenic Vertigo - true vertigo as the presenting manifestation of primary cardiac disease." Nature Clin. Prac. Neurol. (2006) 2: 167-172.

This is a case report of a 90 year old woman who presented to the ED after saying that "Everything's going around in a circle" followed by a brief period of decreased consciousness without prodromal feelings of palpitations or presyncope.  In the ED, presence of vertigo was used to rule out cardiac causes, and patient was admitted to Neurology.  Monitoring there revealed periods of transient asystole (14 second pauses) during which the woman had similar feelings of vertigo.  Placement of a pacemaker resolved these episodes.  This case-report also referred to another study summarized next.

3. Low, PA, Opfer-Gehrking, TL, McPhee, BR, et. al. "Prospective evaluation of clinical characteristics of orthostatic hypotension."  Mayo Clin. Proc. (1995) 70: 617-22.

This article examined 90 patients with documented orthostatic-hypotension undergoing tilt-table testing.  When patients were put in an upright position, 88% complained of lightheadedness while 37% complained of vertigo with some patients complaining of both symptoms.

Discussion: I thnk that these studies (along with many others) make the point that using the type of dizziness to exclude causes of dizziness is dangerous and can lead to mistakes.  Other more validated algorithms have been created (such as using "timing and trigger" by Dr. Newman-Toker), which use the onset of symptoms and factors provoking the symptoms to generate a differential.  Also, people experience dizziness in many ways, and the same cause could trigger many symptoms both in the same person and in different people.  As far I could tell, there have been no large scale studies which have particularly looked at errors generated by relying on dizziness symptoms.  At some level, dizzy is just, well, dizzy.