Disorders of Equillibrium Flashcards
1
Q
Balance and awareness of body position in relation to surroundings requires input from 2 of the following 3 systems…
A
- Visual–to judge distance
- Labyrinthine–to judge acceleration and position change
- Proprioceptive–to judge posture
2
Q
A positive Romberg test indicates what?
A
Somatosensory dysfunction (proprioception)
- *With the eyes open, 3 sensory systems (vision, proprioception, and vestibular sense) provide input to the cerebellum to maintain balance
- When pt closes eyes during Romberg test you remove that visual sense => thus, if problem, problem is [propioception] or [vestibular/labyrinth]
- Romberg is NOT a test of cerebellar fx: these pts cannot stand with feet apart with eyes open OR closed
3
Q
Realize the non-specific nature of the complaint of “poor balance”.
A
A sx, not a dx; means different think to different people; so you 1st have to define the symptoms and determine if it is central or peripheral
4
Q
Illusion of movement of oneself or objects around self due to vestibular or neurologic dysfunction
A
Vertigo
5
Q
Vertigo is often accompanied with what symptoms?
A
Sweating and nausea, sometimes associated with hearing impairment or tinnitus.
6
Q
May be caused by vertigo but usually a nonvertiginous state of altered static or dynamic balance due to dysfunction of cerebellum, dorsal columns (sensory), motor systems (central or peripheral) or basal ganglia
A
Disequilibrium
7
Q
Lightheadedness or impending LOC often due to orthostasis, arrhythmia, hyperventilation and aggravated by high temperature, prolonged standing, large meals
A
Presyncope
8
Q
Vertigo is often due ot vestibular dysfunction of what structures?
A
Semicircular canal/otoliths
9
Q
What are the main characteristics of sensory causes of Disequilibrium?
A
- Problem with propioception
- Visual impairment
- Compensated vestibular disorders
- Worse in dark
- Romberg sign
10
Q
What are the main characteristics of motor causes of Disequilibrium?
A
- NO Romberg Sign
- Mechanical (arthritis)
- Peripheral or central (motor function).
11
Q
What are the main characteristics of cerebellar causes of Disequilibrium?
A
- NO Romberg sign (cannot stand with feet together with eyes open or closed)
12
Q
Peripheral/labyrinthine structures important to maintain equilibrium?
A
- 1. Utricle
- 2. Saccule
- 3. Semicircular canals
- 4. Vestibular nerve
13
Q
Central structures important to maintain equilibrium?
A
- Cerebellum
- Vestibular nuclei
- Vestibulospinal
- Proprioceptive pathway
14
Q
With Peripheral/labyrthine causes of dysequilibrium:
what is the vertigo like, duration of nystagmus, direction of nystagmus, and neuro symptoms?
A
- Intense vertigo
- Brief nystagmus
- FIXED horizontal/diagonal nystagmus (may be latent)
- NEVER neuro symptoms
15
Q
With central dysfunction leading to dysequilibrium what is the vertigo like, duration of nystagmus, direction of nystagmus, and neuro symptoms?
A
- Mild vertigo
- Persistant nystagmus, which can be in vertical direction, but can change directions
- Usually some neuro symptoms
16
Q
Is N/V more intense in central or peripheral causes?
A
Peripheral (intense)
17
Q
Hearing loss is MC with ____ causes of dizziness.
A
Peripheral; rare in centrla
18
Q
6 peripheral causes of vertigo
A
- Benign positional vertigo
- Vestibular neuronitis
- Meniere’s Disease
- Superior canal dehiscence
- Mal de Debarquement
- Drug induced ototoxicity
19
Q
Most common cause of recurrent vertigo and characteristics?
A
- Benign Positional Vertigo: Brief recurrent episodes of vertigo triggered by changes in head positon
20
Q
- What is Benign Positional Vertigo thought to be due to?
- How is this diagnosed?
- Direction of Nystagmus?
A
- Debris floating in endolymph of semicircular canal, MC posterior semicircular canal.
- Dix-Hallpike maneuver w/ affected ear down => causes TORSIONAL nystagmus
- Torsional
21
Q
Dix-Hallpike maneuver should NOT be done in ________.
A
Spontaneous nystagmus, because you are trying to PROVOKE the nystagmus. Thus, only use for episodic.
22
Q
BPV due to debris in horizontal semicircular canal
- Test:
- Nystagmus
A
- Supine Roll Test (Pagnini-McClure)
- Horizontal; changes direction
23
Q
BPV due to debris in anterior semicircular canal
- Test:
- Nystagmus
A
- Dix Hallpike with the affected ear UP
- Downbeat and torsional
24
Q
A patient with vertical positional nystagmus, such as seen in BPV with anterior semicircular canal affected requires what?
A
CAREFUL assessment to R/O brainstem or cerebellar lesions.
25
Treatment for **Benign Postional Vertigo?**
1. Goes away on its own in a few weeks
2. Positional exercises helpful: **Sermont manuever**
3. Meds such as: **vestibular suppressants**, **antiemetics**, and **anxiolytics**
4. **PT: vestibular rehab/balance therapy**
26
How does **Vestibular Neuronitis** differ from BPV?
- Spontaneous attack of vertigo, typically l_asting up to 2 weeks_ (findings similar to BPV) due to inflammation of CN 8; acute vertigo, N/V that peaks in 24 hours & **NO** hearing loss or tinnitus
- But is _**NOT** positonal_
27
What are the characteristics of **Meniere's Disease** and who is most often affected?
Hallmarks?
- _Recurrent_ _episodes_ of _spontaneous_ vertigo, lasting _\>20min to hours_, but less than 24 and _dysequillibrium_ that can last several days.
1. - Hallmark = **Low frequency hearing loss**
2. - **Tinnitus**
3. - **Aural fullness "fullness in ear"**
- **Woman** are 3x more affected (20-50YO)
28
What is **Menieres Disease** thought to be due to?
⬆︎ in the volume of endolymph in labyrinthe because of poor absorption (endolymphatic hydrops)
29
**Treatment** for Meniere's Disease?
Get rid of excess fluid (1 &2\*\*)
1. **-\* Sodium restriction**
2. **-\* Diuretics: thiazdies, furosemide**
3. - Sympmatic: lorazepam and diazepam
4. - Sugery: endolymphatic sac decompression
30
What are the characteristics of **Mal de Debarquement ("Sickness of Disembarkment")?**
Duration?
Treatment?
1. - Illusion of movement as an after effect of travel (**sea**, car, train)
2. - Rocking, swaying feeling after getting off a boat almost immediately after the precipitating event (RARELY true vertigo)
3. - Duration = usually \<24 hours; sometimes longer
4. - Tx: meclizine, scopolamine, benzodiazepines (dizziness meds)
31
What are some of the **drug induced** causes of **peripheral disequilibrium?**
1. Alcohol!
2. Antibiotics - aminoglycosides, tetracycline, vancomycin
3. Aspirin (salicylates)
4. Diuretics
5. -Chemotherapeutics: cisplatin, methotrexate, vincristine
32
Disorders that are **central causes** of **vertigo/dysequillibrium**
* **1. Vestibular migraine**
* **2. Infections**
* **3. Toxins/metabolic**
* **4. Cerebellopontine Angle Tumors**
* **5. Chiari malformation**
* **6. SCA (spinocerebellar ataxias)**
33
What are the requirements of diagnosis for a **Vestibular Migraine (central)?**
1. At leas**t 5 episodes** of moderate/severe **vestibular sx's** lasting **5min =\> 72 hours**
2. Current or previous hx of migraine w/ or w/o aura
3. At least 50% of episodes have 1 or more migraine features: HA (unilateral, pulsatile), photophobia, phonophobia, nausea, aura...
34
**Central: Vascular (ischemic)** causes of equilibrium disoders are most commonly seen in?
**Elderly**; abrupt onset with ischemia of labyrinth, brainstem or both.
35
**Repeated** episodes of _isolated vertigo_ **without** _neurological symptoms_ should always suggest?
**A non-neurologic cause**
36
What helps to distinguish **brainstem lesion (esp. stroke)** from **peripheral lesion** in a patient with an **acute** (not chronic) **vestibular syndrome.** More sensitive than MRI to detect acute stroke.
**HINTS Test**: Head Impulse-Nystagmus-Test of Skew
1. Test **nystagmus**: spontaneous and gaze-evoked
2. Test **skew deviation:** look for ocular misalignment (tell pt to look at docs nose and cover each eye; do many times)
3. **HIT** (Head impulse test): move laterally 20 degrees and return rapidly back to midline everytime; switch
37
When is a HINTS test **abnormal =\> central cause/stroke?**
1. **NL HIT test**
2. **Nystagmus that is bidirectional** or changes **direction**
3. **Presence of skew deviation**
38
HiNTs exam=\> **peripheral vertigo**
1. **Positive/ABNL** head impulse test,
2. **Unidirectional** and **horizontal** nystagmus,
3. **Negative** skew test
39
What **bacterial** **infections** =\> central cause of dyequillibrium
1. **Meningococcal**
2. **Pneumococcal**
3. **H. flu**
40
If you see a vertical nystagmus, think of ______ as the cause.
**_CENTRAL_ = almost always pathomneumonic for brainstem dysfunction**
- Can also be BPV due to anterior semi-circular canal.
41
How to perform **Dix-Hallpike Maneuver** for **posterior- BPV?**
* 1. Have pt sit on bed.
* 2. Turn patients head 45 degrees TOWARD L ear
* 3. Lay patient down, with head hanging off bed and look at eyes.
* 4. + = Torsional nystagmus (may not occur right away bc there is a latent period)
42
What are **metabolic and toxic (centra**l) causes of dizziness?
1. **VitB12 deficieny**
2. **Hypothyroidism**
3. **Wilsons Disease**
4. **Toxins: glue, ethanol (chronic alcohol affects cerebellar vermis)**
43
1. What are **Cerebellopontine Angle Tumors** that are _central_ causes of dizziness?
2. What do they usually affect?
1. Acoustic neuroma (Schwannoma)
2. Meningioma
3. Cholesteatoma
Usually affect **CN 5, 7, 8.**
44
What is the first sign and the first symptom of a **Cerebellopontine Angle Tumor?**
1. **- First symptom** = hearing loss (CN VIII)
2. **- First sign** = absent corneal reflex (loss of CN V and VII)
45
**Paraneoplastic Cerebellar Degeneration** is a _central_ cause of dizziness: they can PRECEDE cancer diagnosis.
1. Most commonly associated with what cancers?
2. Antbodies cross react with?
1. **Breast, ovary** and **lung**
2. Ab to tumor cell antigens that attack **Purkinje cells in the cerebellum.**
46
What are the most common forms of **Spinocerebellar Ataxias?**
Characteristic findings in these diseases?
**- SCA 1 (olivopontocerebellar)**
**- SCA 3 (Machado-Joseph)**
\***Slowly, progressive** cerebellar _ataxia_ of _limbs_ + _brainstem signs_ (dysarthria, oculomotor disturbance, spasticity) + _peripheral neuropathy._ Affect gait early =\> bed confinment =\> all =\> death
47
When is the typical onset of **Friedrich's Ataxia** and what are the common findings?
- **AR** disorder due to mutation on **Chr9** that appears **before 20 YO (young persons disease)**
1. **- Gait ataxia** w/ absent tendon relfexes in legs and muscle weakness
2. - Extensor plantar responses
3. - Pes cavus
4. - Kyphoscoliosis
48
Common cause of death in someone with Friedrich's Ataxia?
**Cardiomyopathy**: death by 35 YO
49
What is the age of onset for **LOFA (Late-onset Friedrichs Ataxia)?**
**After 25 YO: l**ess dramatic course
50
Age of onset for **Ataxia-Telangiectasia?**
Common findings?
- Disease of **infancy** (\<4 yr. of age)
- **Progressive** **pancerebellar** **degeneration** involving nystagmus, dysarthria, and [gait, limb and trunk **ataxia**], **oculoculocutaneous telangiectasia\*\* (port-wine stain from forehead =\> eye)** and **immunodeficiency\*\*.**
- Choreoathetosis, loss of vibration and position sense in legs, areflexia, and disorders of voluntary eye movements
51
What age does **Oculocutaneous telangiectasia** usually appear?
Common findings?
* - Usually appears in **teens**
* **- Immunological impairment** (⬇︎ IgA and IgE) usually evident later on =\> causing **recurrent sinopulmonary infections**
* - Changes of skin and hair, hypogonadism, and insulin resistance
52
* Where is **Spondylosis (degenerative changes of spine)** most commonly seen?
* Can lead to?
* Early signs?
- **Cervical** region
- Can lead to **myelopathy** (spondylotic), compress SC and/or nerve roots
- **Unexplained gait impairment** or **imbalance** often an early symptom in OLDER PPL
53
What will examination of someone with **Spondylotic Myelopathy** show?
1. MCC of myelopath in elderly (\>55 YO)
2. Spastic tone in legs
3. ⬆︎ knee/ankle jerks
4. Babinski signs
5. Variable sensory deficits
54
What can cause **B12 deficiency?**
1. **Malabsorption syndromes** (bc binds to intrinsic factor in duodenum and absorbed in ileum)
2. **Surgery** (gastric bypass, ileectomy)
3. **Drugs** (H2 receptor antagonists)
4. **Nitrous oxide** (whip-its!!!)
5. **Fish tapeworm**
Can all lead to =\> degeneration of **posterior colum** and **lateral corticospinal tract (combined systems degeneration)**; + **peripheral neuropathy** and **dementia**
55
What does **VitB12** do?
* 1. Homocysteine =\> **methionine**
* 2. Methymelonic acid =\> **SucCoA**
56
Clinical fx of Vit B12 deficiency
1. Insidious onset
2. **V tired**
3. **+ Rhomberg and Babinksi**
4. **Gait and balance problems**
57
Diagnosis of VitB12 deficiency
1. **+/- anemia**
2. +/- hypersegmented polys
3. **↓ serum B12**
4. **↑ homocysteine** and **methylmalonic acid**
5. Presence of clinical syndrome
58
What type of syndrome can be caused by **Vitamine E deficiency?**
**Spinocerebellar** similiar to **Friedrich's**
59
The syndrome associated with **Copper deficiency (DECREASED urine Cu and DECREASE serum ceruloplasmin)** can present very similar to what?
**B12 deficiency**
60
How is diagnosis of **Nitrous Oxide Toxicity** made and what is the treatment?
- Diagnosis: **HX** and ⬇︎ **of Vit B12** w/ similar symptoms
- Tx: B12 replacement
