Telestroke

Telestroke is the application of telemedicine to the evaluation of patients presenting with acute ischemic stroke, with the goal of improving access and delivery of care to stroke patients who are unable to be immediately treated by a local neurologist.

Statistics

Every year, almost 800,000 Americans experience a stroke and 90% of these are ischemic strokes. This equates to one American having a stroke every 40 seconds, and unfortunately one will die every four minutes as a result. Stroke is the leading cause of disability in the United States, leaving 15 to 30% of patients permanently disabled after stroke [1].

When a patient presents to the Emergency Department with a stroke, it is essential for the patient to be seen by a neurologist immediately. For every minute the brain is without oxygen, approximately two million neurons are lost [2]. The only FDA-approved medication for stroke must be administered within three, or in certain cases four and a half hours. This medication, intravenous tissue plasminogen activator (IV tPA), while highly effective in improving outcomes in stroke patients, is not without risk, thus requiring a careful neurologic evaluation by a neurologist with training in vascular neurology.

Unfortunately, this medication is underutilized in our country, given only about 2% of the time, often due to reasons such as the narrow time window for treatment, conditions mimicking stroke, hesitancy of non-neurologists to give the medication due to bleeding risks, and very commonly scarcity of neurologists. There are approximately 4 neurologists per 100,000 Americans, making it often difficult for patients to obtain neurological access in emergent situations.

Definition

Telemedicine has been defined as ‘the use of telecommunications technology for medical diagnostic, monitoring and therapeutic purposes when distance and/or time separates the participants [3]. The addition of video to audio for the evaluation of neurological patients, specifically acute stroke, was first described in the early 1990’s, but the term telestroke was coined by Levine and Gorman for the actual application of high quality interactive telemedicine for acute stroke evaluation and/or intervention [4]. The pair envisioned the use of video-telecommunication to connect vascular neurologists 24/7 to emergency room physicians and their patients to provide unlimited access to emergent stroke therapy.

Telestroke Consultation

A general overview of the telestroke consultation process is as follows:

• Rural EMS or triaging ED nurse identifies acute stroke patient enroute or present in ED
• ED physician will examine and obtain brief history and physical assessment to establish possible stroke diagnosis
• Telestroke system activated via direct hotline to telestroke consultant
• Initial laboratory studies and testing initiated
• Patient taken for head CT scan
• When the patient returns from the radiology department, he/she is teleconferenced along with his/her family and the ED physician to the telestroke consultant
• The consultant examines the patient, takes a history from the patient and/or family, and reviews the patient’s head CT scan
• Based on the collected information, a decision is made whether to administer IV tPA and/or to transfer to the telestroke facility for further evaluation and treatment

Technology

Growing interest in telemedicine has led to the development of numerous systems, i.e. BF Technologies (San Diego, CA), Global Media (Scottsdale, AZ), InTouch Health (Santa Barbara, CA), Librestream (Winnipeg, MB), Polycom (Pleasanton, CA), and Tandberg (New York, NY). An example of a commonly used telestroke system is the Intouch telecommunication system [6]. This system recently received FDA approval as a class II Medical Device Data System, and is the only telemedicine system to currently have that distinction.

Most telestroke consultations involve videoconferencing, which utilize high-quality, interactive, bidirectional audiovisual systems. The interactive arrangement allows the patient and family to see the bedside as well as the telestroke consultant, and the consultant can see themselves as well as the patient and family. Most systems allow the stroke consultant to have full control over the camera to zoom, pan, tilt, etc. Video quality standards are generally > 20 frames per second of bidirectional synchronized audio and video at an accurate resolution for a ≥ 13 inch monitor [5]. Common intermediate format (CIF) is used to standardize horizontal and vertical resolutions in video signal pixels, commonly used in high quality videoconferencing systems. CIF equates a video sequence with a resolution of 352x288 at a frame rate of 30 frames per second in full color; multiples of CIF are commonly used [5]. A server is required for data storage, which is normally a computed tomography (CT) scan of the brain, and these are able to be reviewed at the appropriate resolution via DICOM (Digital Imaging and Communications in Medicine) format. Audio transmission has algorithms incorporated to decrease background noise and echo commonly encountered in medical environments.

Recently, several studies have emerged in the literature regarding the use of PDAs and smartphones for telestroke usage. These systems were created to bypass the need for a telemedicine system centered around a robot, thus increasing portability, access, efficiency and interoperability, while also decreasing cost. One study by Takao et al. described their development of a real-time support system (i-Stroke) that used the iPhone and Twitter for the exchange of patient data, images and clinical discussion for the remote management of acute ischemic stroke patients. The reliability of such systems remains undetermined, but potentially useful for mobile consultations [7].

Clinical Evidence

Pooled data from telestroke trials in Arizona (54 patients) and California (234 patients) indicate that more accurate medical decisions were made via telestroke than with a telephone consultation (96% vs 83%; OR 4.2, 95% CI 1.69-10.46; p=0.002) [8]. Additionally, there were no difference in complications (severe or symptomatic intracranial hemorrhage) associated with tPA given via telestroke than telephone (8% vs 6%; p>0.999) [8]. These studies indicate that more appropriate medical decisions are being made, IV tPA is being given more frequently, and hemorrhage rates are lower, and that these appropriate outcomes support the continued development of telestroke networks.

Challenges

Startup costs of a telemedicine network are massive, mostly due to the large amount of capital needed for equipment and technical support. These costs can be further broken down into the telemedicine equipment, information technology support, the necessary clinical and administrative personnel, training and credentialing of personnel, and funding for 24/7 on-call coverage (parallel with on-call stroke coverage) [9]. Annual costs are estimated at $46,000 but can range from less than $10,000 to greater than $200,000, depending on facility size, frequency of consultations, technology selection, etc. [10]. These startup costs are occasionally overcome by research grants or public funding, often in rural or underserved areas. As a result, the majority of telestroke networks are associated with large academic centers in major metropolitan areas serving rural and remote areas.

Reimbursement from insurance payers is another obstacle. Medicare will reimburse for a telestroke consultation only if the spoke patient is connected with the hub consulting neurologist by AV communication, and in situations where the spoke is located in a particular eligible geographic region (Health Professional Shortage Areas, not a Metropolitan Statistical Area) [9]. Of note, New York’s telestroke program is now being supported by the recent approval of Medicaid reimbursement for both physician ends of the telestroke consultation [9]. Although several states have introduced legislation regarding mandatory private payer reimbursement for telemedicine consultation [9], the combination of efficacy and cost-effectiveness studies still are needed to drive the reimbursement trend in the right direction. The American Heart Association/American Stroke Association published implementation guidelines in 2009 (pdf)that address these issues, as well as technical aspects of telestroke [11].

American Heart Association/American Stroke Association Guidelines for Telestroke

In 2009, the AHA/ASA published a scientific statement in an effort to provide an evidence-based review and consensus on this new technology (pdf) [12]. They published class I recommendations supporting the use of high-quality videoconferencing systems for an NIHSS-telestroke examination when a stroke specialist is not available, and that this is equally comparable to a bedside-NIHSS assessment. They support teleradiology use in telestroke, with review by stroke specialists or radiologists to determine thrombolysis eligibility. The AHA/ASA states that a stroke specialist, via telestroke videoconferencing, should provide a medical decision regarding the use of tPA in patients with the suspected diagnosis of stroke when a local stroke specialist is not available. Class II evidence as determined by the AHA/ASA supports the implementation of telestroke consultation, in combination with local stroke education for spoke providers, to increase the use of tPA at community hospitals without access to local stroke specialists.

References

1. Lloyd-Jones D, Adams RJ, Brown TM, Carnethon M, Dai S, DeSimone G, Ferguson TB, Ford E, Furie K, Gillespie C, Go A, Greenlund K, Haase N, Hailpern S, Ho PM, Howard V, Kissela B, Kittner S, Lackland D, Lisabeth L, Marelli A, McDermott MM, Meigs J, Mozaffarian D, Mussolino M, Nichol G, Roger V, Rosamond W, Sacco R, Sorlie P, Stafford R, Thom T, Wasserthiel-Smoller S, Wong ND, Wylie-Rosett J; on behalf of the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics—2010 update: a report from the American Heart Association. Circulation. 2010;121:e54-59.
2. Saver JL. Time is brain--quantified. Stroke. 2006 Jan;37(1):263-6.
3. Hersh WR, Hickam DH, Severance SM, Dana TL, Pyle Krages K, Helfand M. Diagnosis, access and outcomes: Update of a systematic review of telemedicine services. J Telemed Telecare. 2006;12 Suppl 2:S3-31.
4. Levine SR, Gorman M. "Telestroke": the application of telemedicine for stroke. Stroke. 1999 Feb;30(2):464-9.
5. Demaerschalk BM, Raman R, Ernstrom K, Meyer B. Pooled Analysis of the STRokE DOC and STRokE DOC-AZ Telemedicine Stroke Trials. Abstract. Stroke 2010. International Stroke Conference; San Antonio, February 2010.
6. Intouchhealth.com.
7. Takao H, Murayama Y, Ishibashi T, Karagiozov KL, Abe T. A new support system using a mobile device (smartphone) for diagnostic image display and treatment of stroke. Stroke. 2012 Jan;43(1):236-9.
8. Demaerschalk BM, Raman R, Ernstrom K, Meyer B. Pooled Analysis of the STRokE DOC and STRokE DOC-AZ Telemedicine Stroke Trials. Abstract. Stroke 2010. International Stroke Conference; San Antonio, February 2010.
9. Demaerschalk BM. Telestrokologists: treating stroke patients here, there, and everywhere with telemedicine. Semin Neurol. 2010 Nov;30(5):477-91.
10. Demaerschalk BM, Miley ML, Kiernan TE, Bobrow BJ, Corday DA, Wellik KE, Aguilar MI, Ingall TJ, Dodick DW, Brazdys K, Koch TC, Ward MP, Richemont PC; STARR Coinvestigators. Stroke telemedicine. Mayo Clin Proc. 2009;84(1):53-64.
11. Schwamm LH, Audebert HJ, Amarenco P, Chumbler NR, Frankel MR, George MG, Gorelick PB, Horton KB, Kaste M, Lackland DT, Levine SR, Meyer BC, Meyers PM, Patterson V, Stranne SK, White CJ; on behalf of the American Heart Association Stroke Council; Council on Epidemiology and Prevention; Interdisciplinary Council on Peripheral Vascular Disease; and the Council on Cardiovascular Radiology and Intervention. Recommendations for the implementation of telemedicine within stroke systems of care: A policy statement from the American Heart Association. Stroke. 2009;40:2635–2660.
12. Schwamm LH, Holloway RG, Amarenco P, Audebert HJ, Bakas T, Chumbler NR, Handschu R, Jauch EC, Knight WA 4th, Levine SR, Mayberg M, Meyer BC, Meyers PM, Skalabrin E, Wechsler LR; American Heart Association Stroke Council; Interdisciplinary Council on Peripheral Vascular Disease. A review of the evidence for the use of telemedicine within stroke systems of care: a scientific statement from the American Heart Association/American Stroke Association. Stroke. 2009 Jul;40(7):2616-34.

Submitted by: Johanna L. Morton, MD