On Aspirin or Warfarin for Stroke Prevention, Need Dental Work or Minor Surgical Procedure, What to do?

We have previously blogged about the importance of antiplatelet and anticoagulant drugs for stroke prevention.

Let’s say you are taking one of these drugs, and you need to have dental work, or a minor surgical procedure.  Is it safe to hold the drug?  What should you do?

Obviously you are weighing the risk of a recurrent stroke against the risk of complications from increased bleeding during the procedure.

A recent evidence based guideline from the American Academy of Neurology tries to address some of these concerns.

Here is what it says:

If you are taking aspirin, it’s probably OK to continue it while you undergo dental work, skin biopsy, cataract surgery, epidural injections, EMG, endoscopy, colonoscopy and prostate biopsies.

If you are taking warfarin, it’s probably OK to continue it while you undergo dental work, skin biopsy and EMG.

Otherwise, you might need to temporarily hold the aspirin or warfarin for the procedure.

Unfortunately, that is where the guidelines end – There is insufficient data to make formal recommendations about how long these medications should be held for, when they should be re-started, and if patients should be a on “bridging drug” (like Lovenox or heparin shots) while warfarin is held.   These are still decisions that have to made on a case by case basis after careful discussion with your doctor(s).



Memo to Hollywood: Don’t take it personally if Brad Pitt has no memory of meeting you. The World War Z actor, 49, apparently has a difficult time recognizing people’s faces. In fact, he thinks he may suffer from prosopagnosia, or face blindness.

Speaking about the problem in his much-talked-about interview for Esquire magazine’s June/July issue, Pitt says that even if he’s had a “real conversation” with someone, he’ll forget what the person looks like almost as soon as he or she walks away. “So many people hate me because they think I’m disrespecting them,” the actor confesses to the mag.

Prosopagnosia is a rare brain disorder that impairs the ability to recognize faces without affecting other aspects of visual processing.  It is usually caused by a lesion affecting the fusiform gyrus such as stroke or head trauma, although there are even rarer congenital cases.

Perhaps the best known case is “Dr. P.” in Oliver Sacks‘ 1985 book The Man Who Mistook His Wife for a Hat:

Dr P. was a musician of distinction, well-known for many years as a singer, and then, at the local School of Music, as a teacher. It was here, in relation to his students, that certain strange problems were first observed. Sometimes a student would present himself, and Dr P. would not recognize him; or, specifically, would not recognize his face. The moment the student spoke, he would be recognized by his voice …….. At first these odd mistakes were laughed off as jokes, not least by Dr P. himself …….. His musical powers were as dazzling as ever; he did not feel ill—he had never felt better ……. The notion of there being ‘something the matter’ did not emerge until some three years later, when diabetes developed. Well aware that diabetes could affect his eyes, Dr P. consulted an ophthalmologist, who took a careful history and examined his eyes closely. ‘There’s nothing the matter with your eyes,’ the doctor concluded. ‘But there is trouble with the visual parts of your brain ……… ‘What seems to be the matter?’ I asked him at length. ‘Nothing that I know of,’ he replied with a smile, ‘but people seem to think there’s something wrong with my eyes.’ ‘But you don’t recognize any visual problems?’ ‘No, not directly, but I occasionally make mistakes.’

Dr P. illustrates another important symptom in cognitive neurology, anosagnosia. Dr P. is himself completely unaware that he has a problem, he compensates without even knowing it.  It is his wife and students that encouraged him to seek medical attention.

Cerebral aneurysms


Cerebral aneurysms are caused by an area of weakness in the wall an artery, which leads to a bulge or pocket, which can then rupture causing bleeding inside the brain, subarachnoid hemorrhage (SAH).


When we consider patients with cerebral aneurysms, we need to cover these 4 issues and questions:

1. Subarachnoid hemorrhage.  What can happen when an aneurysm ruptures?

2. Clipping vs . coiling.  How are cerebral aneurysms treated?

3. Unruptured aneurysms.  What to do about if an aneurysm is identified on imaging study done for an other reason?

4. Screening.  What should you do if a family member has had an aneurysm or SAH?


Subarachnoid hemorrhage (SAH)


SAH usually presents with a thunderclap headache, which is the sudden onset of the worse headache of your life.  There may also be vomiting, light sensitivity and a stiff neck.

SAH patient with L IIIn palsy (left panel) and subhyloid hemorrhage (right panel).

Physical signs may include a dilated pupil and drooping eye lid (if the aneurysm arises from the posterior communicating artery PComm) and bleeding behind the eye (subhyloid hemorrhage).


Brain CT showing SAH (blood is bright white) tracking around the central arteries (left panel) and spinal fluid from SAH patient showing each tube uniformly red from blood (right panel).

SAH is usually seen on a brain CT scan, although in rare cases (<5%) the CT may be negative, and lumbar puncture may be needed to show blood in the spinal fluid.

Aneurysmal SAH is a very serious problem – One third of patients die before they get to the hospital.   Untreated, another third will another bleed, and two thirds of those patients will die.  Those patients who do not re-bleed can suffer delayed complications, the most serious of which is vasospasm which can lead to ischemic stroke, disability and death.

SAH patients need intensive care on a specialized neurologic critical care unit, and need to undergo further evaluation and treatment as soon as possible.


How are aneurysms treated?


Once an aneurysm is identified on cerebral angiography, there are 2 treatment options – clipping and coiling.

Clipping requires and open operation to locate the aneurysm, followed by the placement of clips around the neck of the aneurysm.

Coiling is performed through angiography – once the aneurysm has been located metal coils are inserted into the sac to cause blood clot to from and obliterate the aneurysm. 

The decision as to which treatment is undertaken is typically made by a multidisciplinary team consisting of a neurologist, neurosurgeon and neuroradiologist, and will depend on the size and location of the aneurysm, as well as the age and co-morbidities of the patient.  In general, patients who undergo coiling have quicker recovery times and the same outcome at 1 yr as patients who undergo surgery and clipping, but they have a slightly higher chance of recurrent aneurysm formation.


What to do about aneurysms identified on an imaging study done for other reason?

Because of the increasing use of brain imaging, we are identifying more and more patients who have asymptomatic (or unruptured) aneurysms.  It turns out that most cerebral aneurysms never rupture.  Furthermore, there is a morbidity associated with the surgical treatment of aneurysms.   However we already know that if aneurysms do rupture and cause SAH the morbidity and mortality is very high.  So, what to do?   To answer this question, we have to study the natural history of unruptured aneurysms, and compare the probability of SAH to the risk of surgical treatment.

SAH table

Risk of aneurysm rupture (and SAH) based on its size and location.

Based on this data, you can see that the risk of rupture is very low for small aneurysms <7mm in size, and increases for larger aneurysms.

Most investigators think that the benefit for aneurysm surgery begins to exceed the risk when the aneurysm in >12mm in size.  Patients with smaller unruptured aneurysms should quit smoking, manage their blood pressure, and undergo periodic re-evaluation for aneurysm enlargement.


What should you do if you have a family history of aneurysm or SAH?

Unruptured cerebral aneurysms are common and familial.  SAH is so devastating and has a poor prognosis.  So who should get elective screening for aneurysms?

For individuals with ≥2 first-degree relatives who have had  SAH, have a 8% risk of harboring an unruptured aneurysm, probably high enough to justify screening.

Individuals with only 1 affected first-degree relative have a higher relative risk of harboring an unruptured aneurysm that is only slightly higher than the general population, probably not high enough to justify screening.

Comparing treatment options for trigeminal neuralgia


First line of treatment for patients with trigeminal neuralgia TGN should always be medical, usually the anticonvulsant carbamazepine (Tegretol®), which provides at least partial pain relief for 80% to 90% of patients.  Common side effects include dizziness, drowsiness, forgetfulness, unsteady gait, and nausea. However, carbamazepine and other drugs prescribed do not always remain effective over time, requiring higher and higher doses or a greater number of medications taken concurrently, causing many patients to experience side effects serious enough to warrant discontinuation.

A study from the 1980s followed 143 TGN patients treated with carbamazepine (CBZ) over a 16-year period.  The drug was effective initially with few mild side effects in 99 patients (69%). Of these, 19 developed resistance between 2 months and 10 years after commencing treatment, and required alternative measures. Of the remaining 80 (56%), the drug was effective in 49 for 1-4 years and in 31 for 5-16 years. Thirty-six patients (25%) failed to respond to CBZ initially and required alternative measures, as did 8 (6%) who were intolerant of the drug.

Surgical treatment of TGN is reserved for people who still experience debilitating pain despite best medical management. Surgical options include gamma knife “radiosurgery” (GKS) and the more invasive microvascular decompresion (MVD).

Another study from 2008 compared outcomes for 80 consecutive TGN patients treated surgically with either MVD (36 patients) or GKS (44 patients) over 4-8 years:



In sum, MVD was more likely than GKS to achieve and maintain pain-free status in TGN,but  both procedures provided similar early patient satisfaction rates.  MVD is therefore preferred for younger healthy patients, while GKS is preferred for older patients with co-morbidies or contraindications, but neither should be considered unless medical therapy has already been tried and failed.

Monmouth’s New Onset Seizure Center Opens in June!


New onset seizures can be isolated events or the harbinger of future epilepsy.

Decisions about starting medications and restricting driving are complicated, and are best made by neurology sub-specialists (“epileptologists“) after a detailed evaluation that usually includes an electroencephalogram (EEG) and brain magnetic imaging study (MRI).

Monmouth Neuroscience Institute is pleased to announce the opening of the region’s first New Onset Seizure Center in June 2013.

Patients who come to the emergency room with their first seizure can be stabilized and then sent home with instructions to follow-up in New Onset Seizure Center, an integral part our Certified Epilepsy Center within one week.

All patients coming to the center they will undergo an EEG, MRI of the brain and a visit with one of our board certified fellowship-trained epilepsy experts during a single visit.

This avoids hospitalization and hasty decisions about medical management.

Click here to find out more about the center.

A more limited role for “stroke rescue”


Recent randomized controlled studies continue to debunk the perceived benefits of mechanical clot retrieval over FDA approved intravenous thrombolysis with tissue plasminogen activator (tPA) for the treatment of acute stroke.

Intravenous tPA  is much more widely available than the costlier mechanical clot retrieval systems.

We recently posted a study that showed both treatments were equally effective for acute stroke treatment.

Another study showed that outcomes were the same for patients who received intravenous thrombolysis alone compared to those patients who received iv tPA and were then transferred to a “stroke rescue” center for mechanical clot retrieval (so called “drip and ship”).

In other words, most stroke patients can be effectively treated at primary stroke centers.


If you think you are having a stroke, call 911 and get yourself to the nearest hospital,

Time is brain!

Mechanical clot retrieval may still be an option for stroke patients who have an occluded artery, but cannot receive tPA because they are on blood thinners, have had recent surgeries, or are seen more than 4.5 hours since stroke onset.

Yet more data that supports the importance of stroke prevention over stroke treatment.

Click here to find out more about our innovative TIA rapid evaluation center, which targets high risk patients for intensive stroke prevention strategies.

Intrathecal baclofen for spasticity in non-ambulatory patients


We have already made several posts about intrathecal baclofen for reducing spasticity and improving function in ambulatory patients:

However, intrathecal baclofen can also be used in patients with spasticity who are non-ambulatory or bedbound:

Normalizing muscle tone may not improve function, but it alleviates pain, allows for better positioning and hygiene, and improves quality of life.

Click here to find out more about our spasticity center.

Neuromuscular respiratory failure

Each lung is composed of >300 million tiny membrane bound sacs of air sacs (alveoli) which if spread out would cover a piece of ground roughly the size of a tennis court.  The purpose of this giant membrane is to exchange oxygen from the air for carbon dioxide from the blood stream.



If the lungs become congested (or filled with fluid) from infection (pneumonia) or heart failure, it becomes harder to extract oxygen from the air:


Treatment includes adding extra oxygen to the air to make this process more efficient.


However, gas exchange across the alveoli can only occur if fresh air is brought into the lungs, and stale air is moved out, a process known as ventilation.  The diaphragm and muscles of the chest wall act like a giant bellows to make this happen:


These muscles can become weak in nerve or muscle diseases such as Guillain-Barré syndrome, polio, amyotrophic lateral sclerosis (ALS), Duchenne Muscular Dystrophy and myasthenia gravis.


These patients are evaluated by pulmonary function testing, which will usually show a low forced vital capacity, low cough flow, and in advanced cases, elevated end-tidal carbon dioxide level.


Patients with this type of ventilatory failure do not need extra oxygen, their lungs can extract oxygen from air normally, they need mechanical assistance moving air across their lungs:




Early neuromuscular respiratory muscle weakness causes nocturnal hypoventilation.  This is because the weakened diaphragm is even more inefficient when laying supine in bed with the stomach contents pressing up on it.

Nocturnal hypoventilation presents with daytime sleepiness, early morning headaches, fatigue, and impaired cognition.


Click here to take an on-line test, and find out how sleepy you are during the day.  If you score 10 or higher, you might have a problem!

Nocturnal hypoventilation is best treated using a non-invasive respirator at night, either with a face or nose mask:



Other patients use a negative pressure respirator vest, or cuirass, which requires the patient to wear an upper body shell  attached to a pump which actively controls the respiratory cycle:



Neuromuscular respiratory failure also leads to an ineffective cough, which in turn predisposes patients to aspiration, retention of secretions, or pneumonia.  Affected patients need to learn to use the cough assist machine when they get a minor respiratory tract infection to help them clear their secretions and prevent pneumonia:

cough assist


More severe neuromuscular ventilatory failure leads to rapid shallow breathing, accessory respiratory muscle use, thoracoabdominal paradox (inward motion of the abdomen during inspiration), and ultimately high blood levels of carbon dioxide.


Thoracoabdominal paradox – Normal (upper) abdomen moves outward with inspiration (diaphragm contraction). NM weakness (lower) abdomen moves in when patient inspires using accessory muscles.

In these cases, respiratory support is needed day and night.

Some patients can continue to use non invasive respiratory support, sleeping with a face or nose mask, and using a mouth piece intermittently during the day:


Others cannot tolerate noninvasive ventilation or have anatomic abnormalities that preclude fitting of noninvasive ventilators.  Some disease, such as advanced ALS and Duchenne muscular dystrophy, affect the upper airway muscles as well as the diaphragm, impairing swallowing and compromising airway protection from aspiration.  These patients can chose to be managed with invasive respiratory support using a tracheotomy and conventional ventilator.



Click here and and here to find out more about the management of neuromuscular respiratory failure.