# US 11,304,658 B2 · Method for diagnosing cerebrospinal fluid hypovolemia

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- Number: US 11,304,658 B2
- Document ID: US11304658B2
- Status: Granted
- Kind: B2
- Application number: 16/536,664
- Filed: 2019-08-09
- Published: 2021-02-11
- Granted: 2022-04-19
- Earliest claimed: 2019-08-09
- Assignees: National University Corporation Kochi University
- Applicants: National University Corporation Kochi University
- Inventors: Eiichi Nakai; Tetsuya Ueba
- Web page: https://patentgrep.com/patent/US11304658B2

## CPC

- A61B 5/4884: {inducing physiological or psychological stress, e.g. applications for stress testing}
- A61B 5/032: {Spinal fluid pressure}
- A61B 5/4064: {Evaluating the brain (for intracranial pressure A61B5/031; for cerebral blood gases A61B5/14553; using EEG A61B5/369)}
- A61M 31/00: Devices for introducing or retaining media, e.g. remedies, in cavities of the body (A61M25/00 takes precedence {; introducing or retaining ophthalmic products into the ocular cavities A61F9/0008})
- A61M 2202/0468: non-physiological
- A61M 2210/0693: Brain, cerebrum
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}

## Abstract

The method for diagnosing cerebrospinal fluid hypovolemia includes injecting saline into a subdural space of a subject in a decubitus position, raising an upper body of the subject, and then determining whether the subject has headache or not, or headache of the subject is relieved or not.

## Claims

### Claim 1

A method for diagnosing cerebrospinal fluid hypovolemia, comprising the steps of:
injecting saline into a subdural space of a subject in a decubitus position, the subject having an orthostatic headache,
raising an upper body of the subject within 5 minutes after injecting the saline into the subdural space of the subject in the decubitus position, and
then determining whether the orthostatic headache in the subject has been eliminated or relieved or not,
wherein the subject is diagnosed as having cerebrospinal fluid hypovolemia in the case where the orthostatic headache is eliminated or relieved, and the subject is diagnosed as not having cerebrospinal fluid hypovolemia in the case where the orthostatic headache is not eliminated or relieved.

### Claim 2 (depends on 1)

The method according to claim 1, wherein, prior to the step of injecting the saline into the subdural space of the subject in the decubitus position, the subject is sitting with the upper body of the subject raised.

### Claim 3 (depends on 2)

The method according to claim 2, wherein the upper body is kept raised until the orthostatic headache is caused, prior to the step of injecting the saline into the subdural space of the subject in the decubitus position.

### Claim 4 (depends on 1)

The method according to claim 1, wherein, prior to the step of injecting the saline into the subdural space of the subject in the decubitus position, the subject is standing.

### Claim 5 (depends on 1)

The method according to claim 1, wherein an amount of the saline is 5 mL or more and 15 mL or less.

### Claim 6 (depends on 4)

The method according to claim 4, wherein the subject is kept standing until the orthostatic headache is caused, prior to the step of injecting the saline into the subdural space of the subject in the decubitus position.