Myasthenia gravis

An autoimmune disease of the junction between nerve and muscle, causing weakness that worsens with use and recovers with rest. It usually starts in the eyes. About one in ten has a thymoma, a tumour of the thymus.

ICD-10 G70.0On the eye and thymus3 stages

Installation

bunx shadcn@4.22.1 add @organui/myasthenia-gravis

This adds myasthenia-gravis.tsx, the disease's data and component, to your components directory. It is built on the disease viewer and reuses the models of the eye and thymus, which install with it.

View registry item JSON

Usage

import { MyastheniaGravis } from "@/components/myasthenia-gravis"

export function MyastheniaGravisDemo() {
  return <MyastheniaGravis />
}

Every structure is a finding: affected structures are amber and spared ones muted. Select one, in 3D or in the panel, to read what the disease does there.

Course

Set stage or defaultStage to one of these. Each stage changes which structures are affected and the investigations to expect; the timeline under the model shows them in order, with the events along the way.

Eyes "ocular" · Onset
Drooping eyelids and double vision that come and go, worse when tired and better after rest. Most start this way, and about half spread beyond the eyes within two years.
- Antibody test: Antibodies to the acetylcholine receptor, positive in about 85% of generalised myasthenia and half of purely ocular disease. Every confirmed case has a CT of the chest to look for a thymoma.
Affects 3 structures of the eye and 1 structure of the thymus.
Generalised "generalised" · Within 2 years
Weakness spreads to the face, speech, swallowing, neck and arms, and fades after rest. Pyridostigmine eases it, steroids and immunosuppressants calm the immune attack, and the thymus and its tumour are removed.
- Pyridostigmine: Slows the breakdown of acetylcholine, so more reaches the receptors left. It eases symptoms but does not change the disease.
- Immunosuppression: Prednisolone, started low and raised slowly, as it can briefly worsen weakness. Azathioprine is added early, after a TPMT blood test, so the steroid dose can come down.
- Thymectomy: Every thymoma is removed, with the rest of the thymus. Without a thymoma, removing the thymus also helps adults up to 65 with antibody-positive generalised disease.
Affects 3 structures of the eye and 1 structure of the thymus.
Or Myasthenic crisis "crisis" · Days
Weakness of the breathing and swallowing muscles, brought on by an infection, surgery, some drugs or stopping treatment, until breathing needs a ventilator. Oxygen levels fall late, so breathing strength is measured instead.
- Intensive care: Ventilation when the vital capacity falls towards 15–20 mL/kg, with plasma exchange or intravenous immunoglobulin, and treatment of the trigger. Drugs that worsen myasthenia, such as aminoglycosides and magnesium, are avoided.
Affects 3 structures of the eye and 1 structure of the thymus.

Scales

Set scale or defaultScale to show the disease on another model. Each has its own structure IDs, so the viewer clears the selection when the scale changes.

"eye": the eye, 21 structures.
"thymus": the thymus, 13 structures.

Without Panel

Hide the panel to place the model in your own layout, and choose the scale and stage with props.

Controlled

Drive the stage, scale and selection from your own state, such as a patient's timeline.

API Reference

Import MyastheniaGravisProps from the same file as MyastheniaGravis.

MyastheniaGravis props
Prop	Type	Default	Description
`scale`	`"eye" \| "thymus"`	—	Control the scale shown.
`defaultScale`	`"eye" \| "thymus"`	"eye"	Choose the scale shown first.
`onScaleChange`	`(scale: string) => void`	—	Receive the scale a reader chooses.
`stage`	`"ocular" \| "generalised" \| "crisis"`	—	Control the stage shown.
`defaultStage`	`"ocular" \| "generalised" \| "crisis"`	"ocular"	Choose the stage shown first.
`onStageChange`	`(stage: string) => void`	—	Receive the stage a reader chooses.
`selectedId`	`string \| null`	null	Control the selected structure ID.
`onSelectionChange`	`(id: string \| null) => void`	—	Receive selections from the model and the panel.
`panel`	`boolean`	true	Show the scales, findings and investigations beside the model.
`timeline`	`boolean`	true	Show the course under the model, with its events and a play button. A disease with one stage has none.
`className`	`string`	—	Set the layout of the model and the panel.

Other props, such as visibility, controls, defaultView and ref, go to the organ viewer.

Models and licences

The component code is MIT. Each model keeps its own licence, and the viewer shows its credit; see Licences before hiding it.

Thymus: BodyParts3D / Anatomography, © The Database Center for Life Science. CC BY-SA 2.1 Japan. Adapted by OrganUI., CC BY-SA 2.1 JP.

Educational, not for diagnosis or clinical decisions. The findings summarise typical disease; individual patients differ.