Cognitive rehab shows promise for stroke patients

Medical Tribune September 2009 SFI
David Brill

A cognitive rehabilitation program used after traumatic brain injuries could also help stroke patients to overcome lingering attention deficits, a new study shows.

Stroke survivors who received Attention Process Training (APT) within 4 weeks were better able to concentrate on visual and auditory tasks 6 months later, New Zealand researchers reported in the journal Stroke.

It is the first study to test APT in an important but neglected area of stroke rehabilitation, the researchers say. Concentration problems are very common in stroke patients – affecting quality of life and contributing to poor functional outcomes – yet specific interventions remain largely unstudied.

Singapore stroke expert Dr. Nagaendran Kandiah, a consultant neurologist at the National Neuroscience Institute (NNI), said that APT could be a useful tool for local patients but that equivalent programs would need to be tailored to the language and culture. Researchers at the NNI are already “actively working on this”, he said.

Further research is also needed to better establish the local prevalence of post-stroke attention deficits, he added. Preliminary data from NNI suggest that about 15 to 20 percent of patients have cognitive difficulties, including poor attention, following a stroke.

“There is a significant amount of literature that shows that cognitive training is useful for post-stroke patients. The awareness that attention deficits and other cognitive deficits are common and can be potentially treated needs to be emphasized both to the public and medical community,” said Nagaendran.

The Stroke study researchers randomized 78 stroke patients to receive standard care alone or standard care plus up to 30 hours of APT (mean 13.5 hours). [2009 Jul 23; Epub ahead of print]

APT patients scored significantly better on the Integrated Visual Auditory Continuous Performance Test (IVA-CPT) Full-Scale Attention Quotient (FSAQ), at 5 weeks and 6 months after randomization. The test measures reaction times to auditory and visual stimuli, and can distinguish between genuine attention to the task and impulsive responding.

There were however no significant differences between the groups in other cognitive performance indicators, or broader outcome measures such as the Physical Component Score.

Lead author Dr. Suzanne Barker-Collo, a clinical psychologist and senior lecturer at the University of Auckland, said that she was disappointed that the intervention did not show benefit across other domains but was pleasantly surprised at the magnitude of effect on the primary outcome.

“We were expecting maybe half a standard deviation difference between the groups, and the effect we found was about four times that,” she said.

There are several cognitive rehabilitation packages available but very little evidence on how best to use them in stroke patients, added Barker-Collo, whose ongoing research seeks to better delineate the profile and time course of cognitive deficits after stroke. She is also reviewing the data from the present study to identify factors that could predict which patients will respond best to APT.

“I think cognition after stroke in general has been ignored to some degree,” she said. “A lot of rehabilitation time is spent on more physical tasks like walking, bathing and dressing – it’s very practical but very often the time spent on that means that not as much time is spent on other things like attention and memory, which are a bit less obvious but can still impact on other functional outcomes. Attention deficit in particular is a very, very common problem.”

Nonadherence to epilepsy medication triples risk of death

Medical Tribune August 2008 SFVII
David Brill

Patients who do not take their epilepsy medications have a threefold higher risk of death, a recent study has shown.

Researchers from the US studied health insurance claims data from 33,658 people over nine years and divided them into quarterly periods defined as either adherent or nonadherent to medication.

They found that the hazard ratio for mortality during nonadherent quarters was 3.32 (95 percent CI 3.11 – 3.54). These periods were also associated with significantly more emergency department visits, hospitalizations and fractures.

“These findings suggest that nonadherence to antiepileptic drugs can have serious or fatal consequences for patients with epilepsy,” the researchers wrote in Neurology.

They also report that nonadherence was more common among males, patients aged over 65, and African Americans.

Lead author Professor Edward Faught, who is director of the University of Alabama Epilepsy Center, said that doctors should educate patients about the need to take their medications but should be careful not to frighten them excessively.

“It might be counterproductive to be blunt and say ‘if you don’t take your medications you may die,’ but I think it certainly is appropriate for physicians to tell patients that there’s good evidence that serious injuries and hospitalizations, which could result in permanent or fatal results, are known to occur if medications are not taken regularly,” he said.

Faught added that primary care physicians are well placed to discuss medication adherence with their patients, as they typically see them more often than neurologists and may have a better personal rapport.

“It’s important once one initiates a dialogue with the patients about adherence to go further and find out what the problems are,” he said.

“Do they think that it’s not necessary – that they can take it just occasionally and they’ll be fine? Is the medication causing side effects? Is it an economic issue? Or is it simply a problem with the daily schedule?”

The research was based on Medicaid data from Florida, Iowa and New Jersey, compiled between January 1997 and June 2006.

One limitation to the study is that the database does not provide information on the specific causes of death and it cannot be proven that epilepsy was responsible, Faught said.

Dr. Andrew Pan, a consultant neurologist and epileptologist at Mount Elizabeth Medical Centre, said that the same principle applies to the increased incidences of hospitalization and fractures, which were not necessarily caused by epilepsy.

He added that the findings may not be applicable to the general population as patients on Medicaid are likely to be from a lower socioeconomic group.

“Patient compliance to antiepileptic drugs should be routinely checked, especially if seizure control does not appear satisfactory,” Pan concluded.

“It is important that the patient feels that the doctor is working with them to help them with their quest for seizure control.”

Brain tumor removed using robotic arm

Medical Tribune July 2008 SFVIII
David Brill

Doctors in Canada have become the first in the world to successfully remove a brain tumor using robotic surgery – a procedure hailed as a “breakthrough.”

The team at The University of Calgary took 8 hours to remove a subfrontal meningioma from the brain of a 21-year-old woman using the neuroArm – a magnetic resonance imaging (MRI)-compatible system which is capable of extremely fine movements.

Dr. Garnette Sutherland, the team leader, said that the system had “exceptional capabilities.”

“This is a turning point in the performance and teaching of neurosurgery. neuroArm will improve surgical outcomes as it is less invasive and more delicate in its touch,” he said.

neuroArm combines real-time image guidance with the option to do MRI on demand, providing the operator with superior spatial orientation to that offered by earlier systems. Surgeons using the system can work at a resolution of 50 – 100 μm.

The arm, which can be used to perform both surgery and biopsies, is operated from an external room using a state-of-the-art control panel which offers tremor filtering and motion scaling.

Dr. Tang Kok Kee, a neurosurgeon at Mount Elizabeth Medical Centre in Singapore, described the surgery as “a very good breakthrough.” He added that neuroArm offered good dexterity, and that the removal of operator tremors would allow for great precision.

The patient had a tumor of the olfactory groove which was affecting her sense of smell. She was discharged 2 days after the procedure.

Since completing its first operation neuroArm has continued to perform surgery, including the removal of a very deep-seated tumor located anterior to the brain stem.

“I suspect neuroArm and other robotic systems will have an increasing role to play not only in neurosurgery but in all surgical specialties,” said Sutherland.

World expert leads Singapore’s gamma knife center

Medical Tribune July 2008 SFXIII
David Brill

Singapore’s new gamma knife radiosurgery center, due to open in early July, is to be headed by one of the world’s leading experts on the technology.

Dr. Bengt Karlsson, who has been working with gamma knife technology since 1986, will be present at the opening ceremony and expects to relocate permanently to Singapore by late autumn. His exact role at the center was still to be confirmed at the time of writing but it appears likely that he will be the center’s new director or co-director.

“I believe that we can enhance the reputation of the gamma knife center to be one of the very best in the world,” said Karlsson, who is currently based at West Virginia University in the US.

“Our aim is to have a treatment quality that meets the highest expectations, and I am thrilled to have been given the opportunity to participate in this.”

Karlsson has used gamma knife treatment for more than 4,000 patients, having previously served as director of the centers at the Karolinska Institutet in Stockholm, Sweden and Goethe University in Frankfurt, Germany. He has also been involved with developing the technology in Singapore and has helped train local doctors to become proficient with the system.

“He’s a mentor for most of the neurosurgeons here for gamma knife radiosurgery,” said Dr. Yeo Tseng Tsai, medical director of the new center, adding that he was looking forward to working with Karlsson in future.

The new center was built by ParkwayHealth at a cost of around S$1.7 million. Singapore has been without a gamma knife machine since the closure of the previous center at Singapore General Hospital in August 2007.

“When the gamma knife was down and some of the neurosurgeons had to use the other systems it was obvious that they were not happy,” said Yeo.

“This gives us access to gold standard radiosurgery again, which has been missing for the last year or so.”

Yeo expects the center to treat around 100 patients a year – primarily those with benign well-defined brain tumors but also some cases of arteriovenous malformations, trigeminal neuralgia and rarer types of tumor.

Private patients will typically pay around S$23,000 to S$25,000 per procedure.

Gamma knife surgery uses converging beams of radiation to target tumor cells while sparing the surrounding healthy brain tissue. The technique is attractive for patients as it is quick and non-invasive, and does not require hospitalization.